Cannot open application, getting this error: "The application '1Password 7.app' can't be opened."

Hey there folks-- just registered to say that I've been experiencing this same exact problem. I sent in a support email as well, but the tl;dr is that I can still use the menu bar 1Password, as well as open the full app from the menu bar version, but I get the same system message even after uninstalling and reinstalling, restarting my Mac, etc. It's been happening for a number of weeks and I've sort of worked around it, but I'd love to get a solution for this as well!