Mac app cannot be opened

You may not have the privileges to open the app, the app may be damaged, or it may not be installed. If you aren't an administrator of your Mac, the administrator may be preventing you from using the app. Contact the administrator of your Mac.

1. Why does my Mac say application Cannot be opened 10673?

Why does my Mac say application Cannot be opened 10673?

As far as I could read, error 10673 appears to be due to the fact that you want to open an attachment or a link in an email and macOS then doesn't have a suitable one Browser available as the default browser. This can be quickly checked and resolved by specifying Apple's own "Safari" browser for the Mac.