Thanks for the screenshot and sorry about that alert! This issue will be fixed in 1.2.41, please update your app if you haven't already.
In the meantime, it looks like the remove manager error was a token issue that was fixed by relogin, but we weren't able to determine why adding the guest failed. Can you send us a screenshot with the error if it happens again so we can check the exact time and error message? Thanks! - CANDY HOUSE