Oh my god Steinberg. Still got no answer from the support. I am replying myself since I managed to solve this problem. Not thanks to eLicencer/Steinberg though.
This is how I solved it:
I installed a Installer tracker/monitor to see what files where installed/changed and what registry keys were created on Windows during the installation process of eLicenserControlSetup.exe.
Then I copied the DPInst (DriverPackage with SynUSB64.* files) from a temporary directory that was created during installation - before the eLicenser installation deleted these temp files after installation was “done”.
The error was caused by a faulty checker in the eLicenser-installer. I think it checks for hardware changes in Windows (not sure). It was FAULTY triggered since I have the same computer, I just changed USB ports since I moved to a new house. I know that it triggered something because the eLicenser log file “eLCC_Actions.log” says: “THREAD SWITCH!!!” (yes, with three exclamation marks!) right after the text “USB Driver version”…
So, to solve the problem I manually chose to install/update new drivers for the USB device called “ProtectExecuter” and pointed it to the drivers (SynUSB64.dll, .cat, .inf).
I know I am not the only one that have had this problem triggered, so Steinberg, please fix this. Legit users should not be affected like this.
Huge thanks to myself and my 20+ years of computer engineering.