I can add and delete bookmarks, but I cannot add, delete, or change tags from either the drop-down menu that appears when double-clicking the bookmark "star" or from "manage bookmarks. The option to manage tags appears, but nothing can be entered in the text fields nor are any of the drop-down items selectable.

I have not tried to add, delete, or change tags in several weeks so I cannot pinpoint if this only started with the current version (28.0) or if a previous version.