Hello Darius,
Thank you for getting back to me. As others might still read the post. I have one question on the downgrade you suggested.
As my upgrade where till this point via WS Workstation upgrade process.
I tried to downgrade using, VMware-workstation-full-12.5.5-5234757.exe that I downloaded from the VMware site. Then I got this message executing that file.
Please do not tell me that I have to uninstall VMware Workstation. Because Then I have to set up all my 19 vmnets again. 
Hence how can I save that and to remaining other settings. Then a downgrade isn't a pain.
Thanks again for the fast response.
Bas.