Hi Vladamir,
Unfortunatly this has not solved the problem for me. I see all classes, triggers and pages in the retrieval window, but after pressing the retrieve button it tries for a moment and gives me the same error. Perhaps my issue is not the same as Mark. Included are some screenshots and the XML with the error:
[attachment=9:Schermafdruk 2015-04-15 09.01.42.png]
[attachment=10:Schermafdruk 2015-04-15 09.01.57.png]
[attachment=11:Schermafdruk 2015-04-15 09.02.58.png]
[attachment=12:Schermafdruk 2015-04-15 09.03.04.png]
[attachment=13:Schermafdruk 2015-04-15 09.03.06.png]
I tried doing it through Wifi and with a connected cable. I turned off my Firewall and I ran Welkin Suite as an Administrator. Nothing changed. This happens on both my Laptop and on my Desktop on two different locations. It also happens on our Development (latest version) org and our Patch Org.
Do we require some settings on the Org itself perhaps? Some Api Access settings?
The only version that is working for me so far (and which I saved the installer for, because even that version is better then Eclipse!) is 13.5