What did you do? ================ 1. Go to https://developer.mozilla.org/en-US/docs/Case_Sensitivity_in_class_and_id_Names$move 2. Put Web/Guide/CSS/Case_sensitivity_in_class_and_id_names in the last field 3. Click move What happened? ============== Page move failed. Move was requested for document with slug Case_Sensitivity_in_class_and_id_Names in locale en-US, but could not be completed. (1062, "Duplicate entry 'css_1' for key 'slug'") What should have happened? ========================== Page move should have succeeded (this kind of page moves usually succeed) Is there anything else we should know? ====================================== This is also an operational problem, we _want_ to do the page move.

needinfo myself to provide link to stacktrace from backend.

The following URL: https://developer.mozilla.org/en-US/docs/Web/Guide/CSS/Case_sensitivity_in_class_and_id_names Redirects to: https://developer.mozilla.org/en-US/docs/Case_Sensitivity_in_class_and_id_Names which redirects to: https://developer.mozilla.org/en-US/docs/Archive/Case_Sensitivity_in_class_and_id_Names There may be a bug (?) about moving a page back to a redirect to itself (undoing a redirect)? The errormill server is shutdown, and the traceback is not available. Please open a new bug if this happens again.