This is happening now to our xbox EASHL club for 6v6 100% of the time upon loading into the game.
Someone had adjusted our faceoffs to be different on the powerplay and that worked fine, but we changed it back. The change didn't actually change within the game despite the menu showing it was changed, but we hadn't reset our lobby and were able to play the rest of the night upon those changes that failed. The change for the faceoff involved moving RW to RD and a few other spots around before we were trying to set it back to the traditional positioning.
Coming back the next day anytime we launch in 6v6 games it always crashes for all users no matter the platform. We attempted to change back to the formation we had and that did not fix the issue. We tried changing our custom jerseys to stock ones, still no luck. Some did mention they had applied an xp boost while readied up as well so perhaps that triggered some sort of issue?
The same group of 6 tried games on another club and we were able to play without issue.