Edit Teams and Kick Off mode are broken functions of EA FC26
We play locally and edit teams to make custom squads. We have done this for years on FIFA and there was never an issue until FC25 where the game crashed after you edited teams and tried to play
The issue was fixed FC25 in January. To our disbelief the issue is back in FC26.
Please see 6 others posts complaining about the same issue:
Squad Changes Not Saving / Team Sheets Frozen After Transfers | EA Forums - 12988419
https://forums.ea.com/idea/fc-26-bug-reports-en/creating-players-and-club-transfers/12659772
FC 26 Glitch in Team Sheets after teams edited. Can’t play in kick off! | EA Forums - 12816052
Edit Teams Tab Worthless | EA Forums - 12805292
https://forums.ea.com/idea/fc-26-bug-reports-en/game-crashes--locks-team-sheet-after-offline-club-transfers/13061667
I don't know what else the community can do to get help from EA.