If you use thumbnails within Firedocs editor and if you click on that thumbnail the popup window that opens only displays a "page not found" error:
Datei nicht gefunden
Die Dateien unter chrome://firedocs/content/image/elml_layout.png konnten nicht gefunden werden.
Popup shouldn't show up in the first place.
Path resolved relative to chrome uri (will be changed in future versions).
This Tracker item was closed automatically by the system. It was
previously set to a Pending status, and the original submitter
did not respond within 10 days (the time period specified by
the administrator of this Tracker).
Fixed: link to popup deactivated.