It looks like we have the same (or a similar) bug again. This time with the plugin Real Media Library (https://codecanyon.net/item/wordpress-real-media-library-media-categories-folders/13155134). If I chose a RML-folder (e.g. https://fclandquart.ch/wp-admin/upload.php?rml_folder=1), then I’m forwarded to the dashboard instead of accessing the requested folder, which is exactly the same issue as I had in the previous posts above. If I deactivate the user role editor pro, everything works correctly.
Thanks for fixing it.