I did as told, I don’t have a microphone at the moment so it is a very boring screencast. I describe a bit. As you can see, I have only the two plugins activated. Going on Final Tiles I get an error message. Despite that message I can even create a new gallery (that does even work in posts, not seen in the video) but I cannot get rid of the error messages and I cannot delete any gallery.
If I deactive FileBird everything works fine, when I activate it again the same problems reappear.
I decided to use another media organizer but maybe this helps you and Diego to sort that problem out.
I uploaded the screencast here: https://www.dropbox.com/s/f4uzd67vaxtuoww/w4jc3R1BdT.mp4?dl=0
Happy programming!
wittli
