Internal Error

Tiberian Sun's Internal Error

Red Alert 2's Internal Error

Yuri Revenge's Internal Error

RockPatch's Internal Error

The Internal Error (often just written short-hand as IE) is a general error returned by the Tiberian Sun engine and its derivates. The message itself gives no information about what the error actually was or what went wrong, thus leaving it to the modder to know what could have caused the error and to find the cause in their mod's changes.

If you experience an Internal Error, you should:

1. Check if the EIP reported in your except.txt file matches an EIP for which the IE cause is known (see below).
2. Think about whether a distinctive event immediately preceeded the error (e.g. a unit being built, a weapon being fired, etc.). If this was the case then take a look at the changes you applied to that unit/weapon/whatever and see if there are any mistakes.
   
3. Carefully check your latest modifications, with the help of a diff between the current rules set and the previous, working rules if possible (for this reason, and in case you mess up your code beyond repair, you should always keep recent backups of working code).

Remember that the more code you add at the same time, the more likely it is to introduce multiple bugs and IE causes (and just because you found one mistake in your code, that doesn't mean there can't be another).

Except.txt

If your game crashes because of an Internal Error, a file named except.txt is generated in your game folder. This file is a dump of certain runtime-data from the game at the moment the error occurred and could potentially tell you exactly what went wrong if you knew the engine code.
Due to his research into the game's binary and his efforts to develop the RockPatch, pd has occasionally been able to indicate the area of the engine where the error occurred (for example, an error occurring in the voxel-loading routines may indicate a problem with a custom voxel). However, pd has other commitments and should not be treated as the go-to guy for any IEs you may have. Further more, pd may not neccessarily be able to help - without the source code or a comprehensive understanding of the game's binary the file is of little use. (cp. SYNCx.txt)

According to an early version of Except.txt (which now redirects here), this file includes the full structure and a stack dump of a CONTEXT element.

IEs that share the same cause also share the same EIP: value in except.txt, so knowing that value might help you determine the cause of your IE (see the list of known IE causes (below) which also includes the corresponding EIP). However, it should be noted that some shared IE causes in INI code can yield one of several different EIP values (depending on the circumstance), and that some rare IE causes can actually yield totally random EIP values. As such, if you do have an unexplained IE, you should check all of the known causes.

Known causes of Internal Errors and their EIPs

Since "Internal Error" is the game's response to almost any fatal error, its causes are diverse. Most common are causes related to weapons and warheads, with a missing warhead probably being the most commonly reported cause.
Note that some IE causes may be prevented (or at least have certain limits extended (e.g. CellSpread)) by the RockPatch, which in turn has opened up potential for new IE causes (RockPatch-specific IEs are not listed here).

Some useful tips

If an integer between 0x00812000 and 0x00B78300 appears in the stack, subtract 0x00400000 from it and look at the resulting address in gamemd.exe with a hex editor. If you find some INI flag, you can be almost sure this flag was the one being read when the problem happened and as such its values (or absence thereof) is the problem.

Specific game versions

Yuri's Revenge 1.001

EIP	Category	Cause
004242DB	Animation	Using a TrailerAnim on an animation but not setting a TrailerSeperation (or setting Template:TTL). This is because the default TrailerSeperation is zero, and that number is used as a divisor.
00424A14	Animation	An Animation with Template:TTL set was played, where X was greater than the number of list entries in Template:TTL or less than 0.
0042E7AF	AI	A Construction Yard does not have Template:TTL set and the owning side's AI was present in the game.
0043C2D3	AI	Error code: EXCEPTION_STACK_OVERFLOW Description: The thread used up its stack.
00441C28	Misc	You have set [General]→ShakeScreen= to zero.
004593BB	Misc	See Tank Bunker / Sell Unit IEs
0045EC90	Misc	Multiple reasons, depending on the stack dump in the except: If 00506115 appears near the top of the stack dump - some country (present in the game at the moment, controlled by AI) cannot build anything from [General]→Shipyard=.
0046650D	Weapon	A unit's shrapnel weapon does not exist (see broken-reference causes, below).
00471CA4	Weapon	A unit's initial primary (Template:TTL or Template:TTL) weapon's Template:TTL does not have Template:TTL set, but a weapon in some other weapon slot does. Triggered by one of the following events: Unit was selected by the user and the user moused-over a potential target. Unit was considering potential targets on its own (e.g. the unit was about to fire automatically at a nearby enemy unit). An IFV or urban combat building gains a mind-control weapon via passenger entry or garrison.
004895C7	Warhead	You have a warhead with a Template:TTL greater than 11.
004D5108	Weapon	A unit's secondary weapon does not exist (see broken-reference causes, below), or the weapon's Template:TTL tag is missing or set to blank. Examples: The offending weapon is the unit's Template:TTL weapon, and the unit just finished constructing. The offending weapon is the unit's Template:TTL weapon, and the unit just got promoted to Elite status.
004F8CCD	AI	[AI]→BuildConst= lists less than 3 BuildingTypes and your last [listed] Construction Yard was destroyed or sold while you were on low power, or you went into low power without owning any Construction Yards.
004F65BF	Misc	Some House cannot build anything from [General]→BaseUnit= .
00505E41	Misc	An AI-controlled House which, due to rules(md).ini configuration, is unable to construct a base, received a Construction Yard thus triggering the AI base planning routine. Triggered by the following events: If a player's MCV was mind-controlled by an enemy, that player is killed, and the MCV is then released from mind-control to the neutral side. The only workaround is to make MCVs immune to mind-control (this is done in the UMP). A neutral Engineer (there's an official multiplayer map that has neutral Psychic Sensors which, on rare occasions, can leave an Engineer as a survivor) captures a Construction Yard. More detail: The AI base planning logic kicks in at the moment a player receives a Construction Yard and generates a plan of what buildings to build, in what order. However, the game makes an assumption that any country that can actually start base construction will be able to build at least 3 different BuildingTypes. When that assumption fails (a Construction Yard is received by the civilian house, who cannot build anything), everything goes haywire. For more info on how base planning logic works, refer to the AI Base Planning System article. Interestingly, the civilian house acquiring a Construction Yard via relinquished mind-control (in the same way as for an MCV) does not cause an IE. Clearly this effect was not taken into consideration when mind-control was added to the engine and the AI base planning routine is only called when a Construction Yard is captured or is first created.
0050CD20 0050CD44 0050CD79 0050CDA2 0050CDCC 0050CDF0 0050CE14 0050CE38 0050CE5C 0050CEA2 0050CECC 0050CF15 0050CF2A	AI	The AI is trying to pick a target for the Nuclear Missile or Weather Storm superweapon but is lacking target weighting values for a certain object that exists on the map. You need to uncomment/restore one of the [General]→AIIonCannonXValue= lines. 0050CD20 - An InfantryType with Template:TTL exists on the map. Template:TTL needs restoring. 0050CD44 - An InfantryType with Template:TTL exists on the map. Template:TTL needs restoring. 0050CD79 - A BuildingType with Template:TTL exists on the map. Template:TTL needs restoring. 0050CDA2 - A BuildingType with Template:TTL and Template:TTL exists on the map. Template:TTL needs restoring. 0050CDCC - A BuildingType with a positive Template:TTL value exists on the map. Template:TTL needs restoring. 0050CDF0 - A BuildingType with Template:TTL exists on the map. Template:TTL needs restoring. 0050CE14 - A BuildingType with Template:TTL exists on the map. Template:TTL needs restoring. 0050CE38 - A BuildingType with Template:TTL exists on the map. Template:TTL needs restoring. 0050CE5C - A BuildingType with Template:TTL exists on the map. Template:TTL needs restoring. 0050CEA2 - A BuildingType listed in [[[:Template:TTL]]] → Template:TTL exists on the map. Template:TTL needs restoring. 0050CECC - A VehicleType with Template:TTL exists on the map. Template:TTL needs restoring. 0050CF15 - A VehicleType with a positive Template:TTL value exists on the map. Template:TTL needs restoring. 0050CF2A - A VehicleType which Template:TTL a BuildingType listed in [[[:Template:TTL]]] → Template:TTL exists on the map. Template:TTL needs restoring.
00518369	Warhead	An InfantryType is taking damage from a non-existant warhead.
005D7387	Misc	Not having at least one valid InfantryType with Template:TTL (default) for each house.
005DA453	Network	A crash occurred with the network code around an object called FirewallHelper.
005F4F88	Animation	An Animation has Template:TTL and SOME_OVERLAY is one of the three last entries in [OverlayTypes]. Link to original report
5F5155	Misc	You tried to construct a BuildingType with Template:TTL. Yuri's Revenge 1.001 doesn't support this, only patched versions do.
0062B662	Animation	Having an animation with Template:TTL which does not point to a valid ParticleSystem (see broken-reference causes, below).
0062DCD2	Misc	An overlay type with Template:TTL set has been destroyed, random dice roll determined that the particle specified in Template:TTL should be displayed, but that flag is blank.
0064003C	Misc	If you have a buildable Construction Yard, start its construction, and then cancel it, an IE will occur. Construction Yards should not be buildable - they should only be deployed from vehicles.
0065B73F	Weapon	You have a Weapon whose Template:TTL is less than [Radiation]→RadLightDelay=. (Cause: Integer division is performed on those two values, which yields zero in this case, and then another value is divided by the result - division by zero.)
006AEBB8	Misc	Your ra2md.ini file lists a combination of game mode/map which the game cannot satisfy. This can happen if the range of valid combinations changes between one game session and the next (i.e. because you changed what maps were valid for which game modes in your mod, or you activated a different mod to the one that was active previously). LaunchBase works around this by saving and restoring the game's configuration on a per-mod basis.
006B7D30	Object	An object has a weapon with Template:TTL, but it doesn't have Template:TTL. The latter part is what tells the game to initialize the Spawn Manager for this unit when it's instantiated, the former part tells the game to try and access the Spawn Manager (and it doesn't check if it's been initialized properly).
006EA6AE	AI/Map	You coerced the game into creating an instance of a TeamType that is not defined, either through Map Triggers or through AI Script Actions.
006F1FC6	AI programming	A TeamType has been defined without assigning it a Template:TTL, or a TeamType is being referenced without being defined at all.
006F352E	Weapon	A unit has an Template:TTL weapon specified which does not exist (see broken-reference causes, below), or the weapon's Template:TTL tag is missing or set to blank, and that unit just got promoted to Elite status.
006F72EF	Weapon	A unit has an Template:TTL weapon specified which does not exist (see broken-reference causes, below), or the weapon's Template:TTL tag is missing or set to blank, and that unit just got promoted to Elite status.
006F40A2	Weapon	Started construction of a unit whose Template:TTL weapon does not exist (see broken-reference causes, below), or the weapon's Template:TTL tag is missing or set to blank.
0070031E	Weapon	A unit has a weapon specified which does not exist in the INI (see broken-reference causes, below), or the weapon's Template:TTL tag is missing or set to blank. (Common reason - that unit just got promoted to Elite status and one of the Elite weapons is misdefined.)
007120F7	Misc	You have a BuildingType (which is click-repairable) with Template:TTL or Template:TTL below [General]→RepairStep=.
0071AF4D	Warhead	Detonating a Template:TTL warhead under one of the following conditions: Firing weapon was a shrapnel weapon. Firing weapon was an urban combat weapon (fired from an occupied building). Warhead has a non-zero Template:TTL set.
0073B0C9	Misc	The concept known as "Infantry Linking" can result in an IE, occuring when the linked infantry was modified in a subsequent game mode override file or a map and a human player scrolls their battlefield view to a place on the map where an AI-owned War Factory is located. Don't do Infantry Linking.
0073C762	Art	The artmd.ini entry specified by a VehicleType's Template:TTL tag is missing.
00756B2D	Art	The specified Template:TTL on a VehicleType does not exist.
00772A98	Weapon	A unit has an Template:TTL weapon specified which does not exist (see broken-reference causes, below), or the weapon's Template:TTL tag is missing or set to blank, and that unit just got promoted to Elite status. Also reported to be due to "firing a weapon that has no projectile". This needs testing - missing projectile may be an alternative reason to all 'missing weapon' IEs.
007C9B92	Malformed input	Multiple reasons, depending on the stack dump in the except: If 006DD5D2 or 006DD009 appear near the top of the stack dump - Map contains a malformed Map Action, while parsing it, a number was expected, something else or end-of-line was found instead. Map Actions expect well-formed input. If 00843EEC appears in the stack - Template:TTL is not set to a valid value.
007CAF66	Malformed input	Multiple reasons, depending on the stack dump in the except: If 0075DE19 appears near the top of the stack dump - A Warhead whose Template:TTL could not be processed. EBP value says how many values remained to be parsed when an error occurred - (11 - EBP) is the 0-based index of the problematic value.
Varies, stack dump starts with 0051BB7D	Warhead	A unit was being erased by a chrono weapon but the object that started the erase process no longer exists. When a unit is being erased, an instance of the TemporalClass is linked to it. This class references the object that is doing the erasing. If the object breaks the link under 'normal' circumstances (e.g. the firer is destroyed or moved) then the attack order is cancelled and the TemporalClass is removed. In some rare cases the link to the firer's TemporalClass is not removed and therefore points to garbage memory. Examples of how the IE may occur: Ore harvester with a chrono weapon started an attack but then transformed whilst unloading ore at a refinery before the target was destroyed. Don't give ore harvesters chrono weapons. A vehicle was being erased but then got picked up by a carryall. This is very difficult to replicate - it has only been reported once. The IE occurs when the unit would have been erased.
90900004	Misc	Generic exception, for example, raised when you are missing the snowmd.ini median fix.

Tiberian Sun 2.03

EIP	Cause
00415698	You used a TrailerAnim on an animation but forgot to set a TrailerSeperation.
004C6428	AI does not have any buildings available for it to build. Check Template:TTL=, Template:TTL= etc.
006703D4	WaveClass Sonic exception, normally triggered by a unit with a weapon that has IsSonic=yes set, firing to the south of the screen and the user scrolling up. No certain fix for this as we know, it is a possible error with the games code.
0067159B	WaveClass Sonic exception. Not sure if this is code related, could be end user.
006717CB	WaveClass laser exception. No certain fix for this as we know, it is a possible error with the games code.
0067159B	You have set [AudioVisual]→ShakeScreen= to zero.
006B6AE6	Multiple reasons, depending on the stack dump in the except: If 0066F44F appears near the top of the stack dump - A Warhead whose Template:TTL could not be processed. EBP value says how many values remained to be parsed when an error occurred - (5 - EBP) is the 0-based index of the problematic value.
90900004	Generic exception.

Unverified / lacking information

EIP	Cause
004145BD	An InfantryType has been given a spawn weapon (such as ASWLauncher). (Real reason appears to be the spawned aircraft with a corrupted HVA. Needs verification.)
?	Removing a building from the PrerequisitePower= list, while it exists in one of the (GDI/NODRegular/Third)PowerPlant= lists will cause an IE the moment any of your Power buildings get destroyed or sold as long as you own a Construction Yard. YR mods that remove Yuri's side from the game, should not remove YAPOWR from PrerequisitePower=. (Could not be reproduced thus far.)
?	Calling for an animation that is not listed under [Animations] might trigger an IE. (That can be caused by multiple issues at various EIPs.)
?	Building a unit in-game whose VXL/SHP was inserted in an original game MIX instead of an expansion MIX. (Does this really happen? Sounds more like the mix editor crapping up than simply "game should blow up because you changed stock files".) Further more, why would anyone eschew the normal method of expanding the game. I don't see anyone testing/replicating this so I propose removing it from the list. //Marshall
?	Removing the PadAircraft statement or listing an AircraftType without corresponding section causes the game to crash when you see your MCV in-game (or any other unit of any player).
006F3481	The (elite) secondary weapon (or its warhead) of the object you just selected could not be found (see broken-reference causes, below). (Marshall retested this and found that the EIP for a missing secondary weapon is actually 006F352E (see above). Not sure what is meant by "you just selected" as the IE will occur the instant the unit is created/promoted. Please can someone else confim that EIP 006F3481 is incorrect and remove this entry if so. Although, it begs the question of where this EIP came from? - it was added by DCoder on 2008-03-04 (id 14195)) I'm sorry, I made a mistake analyzing that one. I saw it at C-GEN and analyzed it. But in fact it was caused by the ElitePrimary being wrong, not EliteSecondary. (Though 006F352E in your comment has "ElitePrimary" as the cause as well, I assume you meant 004D5108.) Just cause a certain EIP causes an IE, doesn't mean another EIP cannot cause an IE for the same reason - there are quite a lot of code paths in the game, and under certain circumstances the first EIP doesn't get hit. I just reanalyzed the function which both these EIPs fall under, and I can say this: 006F3481 IEs if (Elite)Secondary is broken, 006F352E - if (Elite)Primary is. The function is responsible for selecting which weapon a unit should use against a certain target in idle mode, the EIP you reported above for (Elite)Secondary (004D5108) is correct, but is only hit if the unit is in Guard mode scanning for targets when promotion happens. [maybe this part should go off to a talk page?] //DCoder (Just tested this a bit more and got several new EIPs for when the unit was promoted (added in this revision), can't seem to get any consistent results - will need to test this further. //Marshall
?	Setting Template:TTL. Default value is -1, positive values do not cause an IE. I have tested this and couldn't get an IE to occur. Are there any specific circumstances that are required to trigger an IE on a map with CarryOverCap=0? Note that, in FA2YR, CarryOverCap defaults to zero so I would expect this IE to have been seen more often if it was really a problem. //Marshall This setting applies when you progress from one campaign map to another. However, I now see that the default campaigns use 0, so there must be something else amiss. A quick investigation shows that this value is not divided by, so there shouldn't be an exception at all... Will contact Apollo who submitted this as the cause. //DCoder
?	Warheads that are not listed under [Warheads] have been reported to cause an IE, although the exact details are not established. It is not neccessary for every warhead to be listed (for example, removing the Grand Cannon warhead from the list appears to have no effect on the game), however there is no reason not to list every warhead. Validity questionable - if someone can replicate this then please provide an except.txt. Simply thinking about this, putting warheads on the list should guarantee their position in the internal array, so if there is anywhere that references warheads by internal array position then this is important. However, even if you change an existing weapon's warhead to a non-parsed one in a game mode file, you still won't get an IE because default warhead values will be used. Because of this, I'm starting to wonder if the reports of un-listed warheads causing an IE are erroneous. If someone can replicate this then please provide an except.txt //Marshall Verified under a debugger - if a weapon exists and links to a warhead that does not, this will not cause an IE, warhead stats will simply remain defaulted. (In other cases, warheads should also remain defaulted but functional. I have not verified every warhead loading location now, but my applicable ini flags tables should indicate whether or not uninited objects cause issues.) //DCoder 12:44, 11 May 2008 (UTC)
?	If a falling paratrooper (who has nearly reached the ground) is killed by an area-effect mutation weapon. Point based mutations seem to be okay (the falling paratrooper explodes) and the Genetic Mutator seems incapable of killing falling paratroopers. If you have an area-effect mutation weapon, you should ensure that all paratroopers are immune to it (this also means that you can't have a buildable paradrop plane and an area-effect mutation weapon in the same mod).
00000000	Placing two buildings on a map in the map editor so that they overlap, and then destroying or garrisoning one of them in-game. Note that this error is intermittent so may not immediately be noticeable. Use FinalAlert's Options → Show Building Outline feature to see the actual areas taken up by buildings, since there are some buildings whose foundation is different from their visual size, and make sure you don't have any buildings that overlap. Given the unusual EIP value (all zeroes) that has been gathered from testing, it may be a corrupt EIP and not a true indication of the source of the error. Note that this EIP has also been gathered from other 'random-EIP' causes. Indeed it is not a true indication, EIP 00000000 can be acquired in several ways. If you can provide an except, I will be able to provide more specific details to look for, like in the case of 0045EC90 . //DCoder

Broken-reference Causes

• Most of the flags that point to an object type do not verify that the object type exists and will try to invoke it anyway. This includes pointers to weapons, projectiles, warheads, particles, particle systems and infantry/unit/aircraft/building types, among other things.
• All object types must be parsed in order for them to be invoked successfully. For example, a weapon must be parsed by being referenced by a unit in the main rules (weapons used in a game mode that aren't referenced in the main rules will not have been parsed, nor will shrapnel weapons that haven't been referenced by a dummy unit).
• Note that all weapons have to specify a Template:TTL tag and the tag must not be blank otherwise an IE will occur. However if the specified Template:TTL does not exist then that will not cause an IE, as the game will use default warhead settings.
• Your object type may not be 'missing' as such, you may just have mis-spelled its ID (e.g. "MagenticBeam" as opposed to "MagneticBeam"). Always check your typing carefully to make sure you don't any words out.

Tank Bunker / Sell Unit IEs

• There are two IEs that can occur after using a 'Sell Unit' superweapon on a tank-bunkered unit. Both of these IEs can yield seemingly random EIP values (due to the fact that, when the unit is sold, the building's "BunkeredUnit" pointer isn't cleared and so points to garbage memory. Attempts to dereference it will be met with varying levels of failure).
• An IE may occur the instant you sell the unit.
• If an IE does not occur the instant you sell the unit, then the Tank Bunker will have been rendered unusable as the walls are still up. If the 'broken' Tank Bunker is sold or destroyed then an IE will occur (this IE does always happen). This IE frequently yields EIP 004593BB, although has been known to yield seemingly random EIP values (for the reason stated above).
• The only way to prevent these IEs is to make sure a player never has access to both the Sell Unit superweapon and the Tank Bunker at the same time. (To achieve this, the building that provides the superweapon must be uncapturable and immune to mind-control as must the Tank Bunker. Further more, unless both buildings are country specials, you will need to remove MCVs from crates and make Construction Yards uncapturable and immune to mind-control too.)

Software used to find Internal Errors

• INI Checker (can check your rules, art and sound files for syntactic errors like typos and missing references)
• ExceptChecker (primarily for RockPatch-related IEs, it analyzes except.txt, tries to find references to code added by the patch or known routines, and might then be able give a direction)
• Debugger (if you know assembler)

See also

• Reconnection Error
• Confirmation the Infantry Linking IE also applies to modifications done by maps