Errors when modifying user profiles

There's a specific example at https://github.com/FAIRsharing/FAIRsharing-API/issues/1385 of a user whose email address cannot be changed because they want the same email address as another account.
The error doesn't make it to the UI and it's hard to see what's happening as there's an immediate redirect upon submitting the data; therefore, users will never see why the edit failed. 
