I have just created an Add-on, uploaded it via the developer center,
but after the screen that specified that it had been uploaded and I
have to edit its details, I got an "access denied" page.
Unfortunately - now my add-on has disappeared - I can't find it
When visiting the add-on / dashboard - it says I haven't uploaded
anything, but when trying to upload it again - I get a message saying
that it already exists.

How can I solve this?

Thank you,