The issue has been closed
in a private repos I cannot 'revert changes of a single file'. I am getting a 'Revert failed - see console for details' message and the following error logs:

after adding the 'personal token' in the extensions settings it works as expected.
would be great to have a cleaner error message that I missed to configure the token
using 19.8.20 in google chrome 78

posted by kidonng over 5 years ago 
I am aware that ‚some features‘ require the token.
A simple console log error telling that the token is missing would be great for UX
posted by staabm over 5 years ago
If it's for great UX then we should use a snackbar or popup instead of console messages.
There are already messages telling you that token may be needed. But your screenshot doesn't contain the error message for revert-file
feature.
(And "Personal token required for this feature" error for another feature can be seen in your screenshot)
posted by kidonng over 5 years ago
Indeed. The token error is already present in the console. We generally expect it to be there and don’t provide extra UI for such errors.
posted by fregante over 5 years ago