There is a while class of errors that result from the user clicking the save button but the server replies that the save has not happened. A reasonably comprehensive list we can think of is:
- API responding with error
- validation error
- merge conflicts
- permission issues
- storage error
- generic errors
Currently in this event the following happens:
{F28940845}
As you can see the user isn't informed what the problem is. They are also not made to leave edit mode (this is probably a good thing or they would be annoyed that their work is lost)
I would suggest that a human readable error message should appear near the save button. It should be made clear that clicking save again will result in reattempting the save action and that this might be successful (e.g. if the failure is due to wikidata being down and it then comes up again) or it may continue to fail (e.g. because the user is blocked).