Hello Again,
im trying to run Your software again 
i tried latest 64bit version, even with GTK backend switch and get errors:
Gtk-Message: Failed to load module "canberra-gtk-module"
Gtk-Message: Failed to load module "pk-gtk-module"
Ofcourse i have installed libcanberra yet still have issues.
System is Fedora, with wayland (yes, still).
Also side question, have you consider to maintain RPMs?
other thing - once i get appimage (few versions before, and it worked just fine, not sure what is the problem here).
Cheers for Your work! Hope ths project gets bigger becouse i think this can be best raw editor out there.