Saw this little post in the Bablyon 5 Mod thread, thought it would be useful for anyone here to know. Will be testing this myself soon. Sadly a lot of the errors I get only show up in the dev log, not asserts in game, but better than nothing.
Hint: You can get an idea of what entity file is causing an assert to fire by using ProcExplorer which will list what files a process currently has open. Look a the dev.exe's list of file handles when the assert window is up and the offending entity file should appear in that list.
Edit: Holy crap, this tool is amazing! Wish I knew about it years ago. Hunting down these dev errors are trivial now when you know the file to look at.
Some common ones I had, not sure if these issues are known.
m_aiUseTime == AIUseTime::Invalid
If you have isAutoCastAvailable FALSE, aiUseTime and aiUseTargetCondition must be "Invalid".
duration > 0.0f
You have a nonbeam weapon with a duration property greater than 0.
Assert @ D:\projects\SINS\SinsRebellion\main\CodeSource\GS/Entity/Interfaces/IBuff.cpp(4109)
You have a finish condition of "Invalid" in a buff file. This is no longer supported, just use no finish conditions instead.
Assert @ D:\projects\SINS\SinsRebellion\main\CodeSource\GS/Entity/Interfaces/IBuff.cpp(2741)
The game doesn't like "ApplyBuffToTargetsLinked" instantActions having ownerships other than "Player". I actually have a case where this is necessary however and IIRC it works fine.
Assert @ D:\projects\SINS\SinsRebellion\main\CodeSource\Engine/String/StringLibrary.h(83)
result == 1
I couldn't figure out what was with this one. Weird thing is, the file this was thrown on was an almost exact copy of another entity, only for a different faction.
There were a handful of errors that didn't show up in ProcExplorer, but for the initial validation at least where most of the errors are thrown, this is a fantastic tool that everyone should try. Hunting down these assert errors is one of the best ways to improve mod stability, and if you're experiencing crashes after some of these, this should help you narrow down the culprit.