Interesting, frest install of the #6007 worked fine, so tried resetting the setting on my main install by moving them to different place so can restore if want to. Game working again, but the second I change some of the settings, like for example which tileset to use or whether to use a tileset at all, get the error when trying to save the settings. Adding any kind of autopickup rule gives the error also when trying to save them. Some other settings, like temperature unit used for example, can be changed and saved without problems, didn’t go through all the options.
Rolled back version by version getting the error on 6007, 6006, 6005, 6004 until version #6003 works fine, so I guess that was the version I was using yesterday.
Trying to change aforementioned settings/autopickup on 6007, 6006, 6005, 6004 gave the error too. Adding an empty pickup rule doesn’t give error, but even a single letter does.
In case it matters, i5-2500k@4GHz, 970GTX, 16GB ram.
Win 10 64 bit set to english region, using finnish keyboard layout, Ive noticed a lot of localization changed in the game, so mentioning these.