my playbook reset to default in the middle of the season. It's the second time in three seasons and probably the tenth time ever. I'm assuming it's from overrides and it seems like it happens the more complex situations get.

It's a half season of adjusting all reset but importantly it is a automatic loss cause the players are in on plays they shouldent be and the plays are random garbage plays for the most part.

Is there any way to guarantee this won't ever happen?

i had that happen in a playoff game in league 2 many seasons ago. I'm not sure what i did but i lean on the result being from me accidentally hitting the load default playbook button. It's definitely obvious though when you see the runs being called, lol

Pretty sure it's not the reload button.

The reasons the AI will set your game plan (these checks happen at every game stage, whether or not your team is playing):

1) The team is owned by the AI (in the interest of being comprehensive I have to include this first check.)
2) You have fewer than 30 plays selected across your entire gameplan or more than the maximum number of plays
3) You don't have any offensive plays selected
4) You don't have any defensive plays selected
5) You have too many plays scouted

That's it. If the AI resets your gameplan, one of those tests failed. Some factors that may impact #s 2-4 could be hiring a new head coach that doesn't have the same playbook. Also you -may- be scouting too many plays if you have filters on and don't realize it, but you should get a warning if you do; don't ignore the warning box if it appears on your scout screen.

Wait, am I understanding this correctly.

In our ENTIRE Game Plan, COMBINING Offensive and Defensive, we only HAVE to have a Minimum of 30 Total Plays?

Yes, this was a request back in the original beta - at the time I didn't foresee any problems with it. I haven't changed it because, even if I do require you to select a full set of plays, it is easy enough to build a gameplan that ignores all but a select few.