No it is not usual. Exactly when is the crash happening? Knowing that may help us figure out the cause.
- are you getting the small box which shows the stages of loading? - maybe a cache problem
- do you get to the end of that box and then it crashes? - maybe a graphics glitch
A CTD with no message most often happens when something has gone wrong with one of the graphics assets. Usually units but sometimes terrain graphics. For example a file being mistyped in one of the art define files. If you have not been modding v27 this is unlikely. If you have then you should check any graphics definitions you have changed to make sure the file names and locations are right.
Are you trying to play on a predefined map that comes with v27? I thought we had fixed all of them but we may have missed one.
Otherwise while waiting for someone to look at your mini dump file you could try deleting the contents Caveman2Coamos/Assets/Cache folder and trying to start the game again. The cache will be rebuilt.
If he can't even load the mod, but could previously (same version too) then it's probably some sort of caching problem, as you suggest, so clearing that would be a good place to start.