Are you having trouble with Microsoft Teams on iOS crashing every time you try and open a particular chat? If so, I hope this does the trick for you!
I actually encountered this issue because of testing I had done in my previous post on issues with adaptive cards displaying in Microsoft Teams.
If you refer back to that post and follow the steps to reproduce an issue with Microsoft Teams being unable to render an adaptive card with version 1.5, and you post that “invalid” card to a Microsoft Teams chat, and that is the last message in that particular chat, the iOS Microsoft Teams app will crash each time you try and load the chat. Signing out of the Teams app and/or restarting the device won’t resolve the issue.
The fix? Post a valid message to the same chat, so that the “invalid” adaptive card isn’t the latest message, and it will begin loading again in iOS Microsoft Teams. You can easily do this by typing a message in the desktop version of Microsoft Teams, which thankfully isn’t affected by this issue.