I currently have a custom Insert Image Dialog.

I do not rely on the config files and on the settings of the Image Gallery Path, since the logic of my web application is too complex to integrate in these methods.

 

when I have an image in the editor, and I dbl click it, it opens the Tag Editor, it works fine

when in firefox and I dbl click an image, it opens the gecko image dialog, and it gives me the above error.