New user to Dopus 12 on the PC (currently on 60 day evaluation), but I used Dopus 4 and 5 on the Amiga 1200 waaaaaay back. Found this via an Amiga forum.
Anyway, I think I've found two bugs:
Customise Toolbars > Image Viewer > Image Size > Large - the icons change to large and the setting is saved but the icons revert back to normal size after closing and opening it again. The setting still says "large" though.
Preferences > Thumbnails > Appearance - Unticking the "Make square" box doesn't activate the Apply button. If another setting is changed (which activates the Apply button) and "Make square" is unticked at the same time, then clicking Apply has no effect on "Make square" and the option is ticked again when going back into preferences.
Liking it very much so far!
-EDIT- Meant to say I'm running DOpus 12.20 64 bit in Pro mode on Windows 10 64 bit.