C++ Runtime Error

[Makanyane]

Help!!!!

Have extensively modded BI 1.6

Running on -ai to test I am now getting a R6025 'pure virtual function call' C++ Runtime error at apparently random times. See pic:
https://img86.imageshack.us/img86/9337/runtime8iv.jpg (https://imageshack.us)
Any idea if any thing I modded could have caused this (have changed text files and 2D graphics only) or would this just be from a corrupted .exe or dll's?

If so can modded text files etc. be the cause of corruption?

EDIT: have now reversed out a couple of days worth of changes, seems it could have been something in that (not entirely sure yet as above error wasn't consistent), had made changes to cultures including reassigning factions to different existing cultures and changing building.tga's for 'eastern'. Above error only came up after 80 + turns, so could it be to do with reaching certain city size / building?

[edyzmedieval]

Hmmm... It might be from corrupted dll's but since you haven't modified anything, you can run the dll's out.

It might occur from some culture mixes, because I(personally think this) that they are somehow related to the dll stuff. They are very related to the game engine methinks because it establishes a connection somehow between the game engine and the "outer" engine. :juggle2:

:idea2:

[Makanyane]

Culture mixes sounds likely, however, can you explain in any more detail what effects; game engine v. outer engine?

Thanks anyway.