Just to confirm, are you still getting the error message you sent above? Or is sending feedback closing the browser the only problem persisting?
First, do make sure you file feedback about the issue from Stable, since you're able to!
Second, are you logged in to your profile on Canary? Can you try opening an In Private window of Canary and sending feedback there? (That will help identify if this is a profile issue, extension issue, or something similar)
Third, what OS and version are you on?