Thank you for reporting this problem!

Just FYI if you look at the server response it should say what exactly went wrong.
It might be useful to include this information into this bug report.

Yes thank you. The message is fine duplicate key value violates unique constraint "map_unique_name", its just that the error code is not appropriate.

The user-facing error message is also not ideal. There should be a different status code for duplicated maps, so that we can be sure. (And don't need to say "maybe" it is a duplicated map).

A better solution would be to directly validate the map name while typing, though.

@tschawax do we need an extra endpoint to check for duplicate map names or can we have better usability by simply having a different return code for duplicate map names?

I would go with the 409 Conflict code which is one of the mainly used ones for such "something already exists" scenarios.
And I agree that the server response should explain what's wrong.
And I also agree that we should remove the maybe and change the error/info message in the frontend to sth like Tut mir leid, eine Karte mit diesem Namen existiert bereits.

Ok, 409 Conflict sounds reasonable, I updated the top-post.

error/info message

I would prefer if the user would not get a toast but see a message directly at the problematic field, ideally while typing.