Hi - replying to a really old bug here - Do you have a /etc/geeqie folder and a /etc/geeqie/geeqierc.xml file?
If not, check in $HOME/.config/geeqie/geeqierc.xml - If you have a line containing your mentioned option (image.dither_quality) in either of these files, simply remove it from either file. (If I add it on an up to date geeqie 1.4+git20180820, I do get the warning you are mentioning, but it then removes the option, and I don't get the warning on subsequent startups of geeqie). So, it should be safe to simply remove the option. - I intend to close this bug. -- Andreas Rönnquist [email protected]

