I've installed Immunet on a 2012R2 server. The server is a new install VM used as a test bed. I was wanting to test Immunet before using it. If I click "Update Now" on the main page, the dialog box that pops up will get new definitions, but the first message it lists is "Could not connect to the update server (error 0), please try again. If the problem persists, please contact Immunet Support."
The version of Immunet is 188.8.131.5238. The VM has been rebooted and this has continued for a couple of weeks.