I'll just leave this right here and wait for you to tell me what to do.
http://imgur.com/a/3IIdW
Was this game new with the A15 release, or an old game? If an A15 game, which A15 build was it created with, and which one are you attempting to run it with?
I saw this too after loading an older A15 save under a newer build. This is totally separate from the error log window that appears, so turning off 'auto-open on error' doesn't help. If resaving the game doesn't help then I would stop using save games from an older build - start a new one.
@ alxddd - As CannibarRechter says above, can you please confirm precisely which version of A15 you are trying to load this save file with, and which version of the game was the save file created with.
A15 is currently an unstable test build, so it is probably more likely than not that you will encounter problems continuing A15 saved games if you update to a new test version between playing sessions.
Yeah, it's a save format change, not a bug. Thanks for reporting.