An error occurred while opening a virtual disk. Verify that the converter server and the running source machines have a network access to the source and destination ESX/ESXi hosts

Hi everybody,

I ran across this infamous error now on my machine. I tried several other suggestions from other posts with no luck. I am trying to convert a powered off VMware Infrastructure machine (template) into a Workstation image. I get this error immediately after I select the template as the source and click next.

Any hints? I even tried to reinstall Converter (5.5) completely...