2
On Mac, when trying to open any file, the following error box from Finder comes up -
When right-clicking the file and choosing Open As, though, the file opens just fine with the chosen application.
Joseph A.
Posted 2017-01-07T03:14:26.860
Reputation: 1 844
2
Best guess is it's lost its default app for that file type.
Not sure quite what it thinks it's replaced it with, never seen that particular error before.
Fix may be as simple as selecting one file of that type, right click & Get Info, then change the default 'Open with' to a known good app, then 'Change All…'
Tetsujin
Posted 2017-01-07T03:14:26.860
Reputation: 22 456
Then this couldn't possibly be your solution- so you downvoted it because you looked up the wrong question ? – Tetsujin – 2017-07-14T06:51:16.533
1Well, it's the wrong question because this situation can only happen when opening a document. If an app won't open, then it's not relevant to this QA & should probably be asked as a separate question. – Tetsujin – 2017-07-15T17:40:04.320