I just noticed that Dmitry replied only to me, so I copy his reply below:
known_hosts' contains Russian/Cyrillic characters. OK if if OS locale is Russian & path to
known_hosts' contains only English
characters.
Frankly, I don't know if generic English/Latin characters belong to
Russian/Cyrillic character set.
Best regards,
Dmitry Mikhailov.Afaik, the patch is applied to both the preview (pre01) and the current release (20141021) of X2Go Client for Windows 4.0.3.0, so it's rather unusual to observe different behavior from preview to release. In my system (Greek Windows 8.1) with a user name in Cyrillic (фисвуа) (fyi, I pressed a-b-c-d-e-f to get it) and Greek locale both versions exhibited the same erroneous behavior (that's why Mike#2 introduced bug #611).
I'll try to set Russian as the main language of my system to see what happens (if I can find my way in Russian and succeed in getting back to Greek :)
George