When we have seen crashes occurring during the transition from Preseason to Spring Training, it almost always has been related to the OOTP schedule. The most common scenario we've seen is this:

When you create a new game, the game generates a schedule for each of your leagues. When you start Spring Training, the game attempts to confirm and load those schedules. If you have changed any aspect of your league structure (teams, divisions, subleagues, etc.) between those two dates, the game fails to confirm and load the schedule when you get to Spring Training, resulting in a crash. Of course, we're planning on addressing this in the future so that failing to do this doesn't cause a crash, but for now this workaround should help:

1. Go to Game | Game Setup | League Setup
2. In the bottom right, choose Functions | Edit Schedule
3. Click on "Generate Fictional Schedule" (Note: If you happen to have a custom schedule for your leagues, this will of course wipe out that schedule. If that's the case, simply re-load your custom schedule for each level instead of generating a fictional schedule.)
4. From the League drop-down in the top right, choose the next league, and repeat the process. Repeat for all of your leagues.

The game should now sim correctly.