This isn't a bug report yet, since I can't reproduce this 100% of the time. I'm making this post to see if anyone else has encounter this, and may add some usable information.
Since R138 (and in R138.2 too), I'm having random crashes on C2, in various cases.
First I had was when switching from an event sheet to a layout in editor. With no reason that I could understand fully, all the sprites started to "forget" their current image, and the program crashed with no bug report to help.
I also had 3 times a crash when just "waiting" in an event sheet, doing nothing but looking through the code (even one time without touching my mouse or keyboard).
The same project 5 min later didn't crash at all, and I could sometime work around 2 hours without problems.
One of the 3 times was just after a restart of my computer,
I never had any problem with C2 since I started using it, and as far as I can tell I didn't change anything with my computer since.
I'm using a windows 7 SP1 up to date, on a x86 processor (intel core i7).
I'm sorry this "report" isn't accurate, and I would love if anyone having similar problem could report it too. If you have any usable information, I'm sure this could help, as this initial post is worthless as it is.