A bit more info...
First, I can now confirm that this bug occurs systematically, regardless of any connection attempt. I just had to start X2go client and wait for the error to pop up.
Second, I have tried to use a recent vcxsrv.exe (installed separately), as the X2go built-in is 1.17.0.0-3". I tried with version 1.19.5.2". No change noticed.
Hope that helps...
L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel antivirus Avast. https://www.avast.com/antivirus