Batchmode license activation error

Hey guys,
I’m trying to activate Unity in batchmode on my jenkins windows slave, but always getting the following error:

Unity.exe -quit -batchmode -serial *** -username **** -password **** -logFile "D:\unity.log" -projectPath "D:/someProject"
BatchMode: Unity has not been activated with a valid License. Could be a new activation or renewal...
(Filename: C:/buildslave/unity/build/Editor/Platform/Windows/WinEditorMain.cpp Line: 836)
DisplayProgressbar: Unity license
[0415/] Can't retrieve a valid WinSAT assessment.^
Timeout while processing request ""
Canceling DisplayDialog: Updating license failed Failed to update license within 60 seconds. Exiting.

The timeout occurs just after a few seconds, and not 60s as mentioned. But when I start unity normal, and activate the license manually everything works fine.

Any suggestions?

Found a workarround to make the activation possible.
Just starting Unity without batchmode, before activating it. It works but isn’t a very good solution.

And just found out license returning also doesn’t work properly. The license is returned and the license file deleted but still getting this error:

LICENSE SYSTEM [2016415 10:6:44] Headers:
    HTTP/1.1 200 OK
    Server: nginx/1.2.1
    Date: Fri, 15 Apr 2016 10:06:44 GMT
    Content-Type: text/xml; charset=ISO-8859-1
    Content-Length: 2183
    Connection: keep-alive
    Accept-Ranges: bytes
    X-Varnish: 2771185406
    Age: 0
    Via: 1.1 varnish
    Set-Cookie: SERVERID=varnish02; path=/

Canceling DisplayDialog: Failed to return license License server request timed out.