My initial thought in reading this is that it's sounds like it's likely a video card driver issue. So the first thing to try would be to check and make sure those are up to date and update them if not. Also, that you are on the latest patch:
https://forums.ootpdevelopments.com/...d.php?t=312448
Now, if neither of those quick fixes work, we'll have to do some more in depth troubleshooting. In which case, we'll need to know as much as possible about your system. So that basically means answering all the questions you'd find in the first post of the crashing thread, as follow below:
So please let us know the following:
Are you on a PC or Mac?
What OS are you using?
Do you have the game on Steam or the Standalone or a different version (please name it)?
If you are on a Mac, what specific model Mac do you have? Also if you're on a Mac please attach the Mac crash report that pops up after a crash.
What are your system specs (especially your video card and your amount of memory)?
Where exactly does your game crash? What are you doing just before it crashes? Can you consistently get the crash to repeat by doing the same thing or is it seemingly random? Do you get an error message? If so, what?
Does this crash in only one saved game or in multiple saves? If only one, then we'll need to see your league files as per the instructions in my sig (or you can just upload to Dropbox/Google Drive and post a link)
It would also help us to have the game generated trace file.
To generate that on a Windows PC, do the following:
If you're on Steam, right-click on your game in the Steam library, then Properties, and on the General menu click on 'Set Launch Options' and enter the word "tracemode" (without quotes.).
If you have the standalone, right-click on the OOTP21 shortcut on your desktop, click on properties and add 'tracemode' to the command line
Then try to start the game again. Get it to crash.
After it does so, navigate to the following folder: Documents\Out of the Park Developments\OOTP Baseball 21\debug
Find the trace file there and post with the rest of your information. That should have some data that will help us figure out why the game is crashing.
Last of all, you'll also want to try experimenting with all the different 3d settings on the settings > 3d and facegen page. Especially the OpenGL mode and audience detail etc.
Then let us know if any of those make a difference, and if so, which ones.
Let me know as much of the above as possible and that should hopefully give us enough info to start tracking down a solution to this.
When you get us the info, please