Don't know if this still applies for Workstation 14.x, but you could try adding the line
vmx.allowNested = "TRUE"
to C:\ProgramData\VMware\VMware Workstation\config.ini
That is according to this old document Running Nested VMs
What version of VMWare DID it work for?
I have no idea which version(s) it worked for. That document, while still useful in many circumstances and a good read for understanding VMware nested virtualisation, is also getting old and stale as the author of that document no longer works for VMware. Many changes have occurred with VMware ESXi, Workstation and Hyper-V itself since the document was last updated.
You have nothing to lose to give that setting a try while having everything else to gain if it works.
Thanks. It actually worked, but only on a Host OS win 7 x64. In Host Os Win 10 x64 I did not have permission/access to edit config.ini.
Right now there is no internet connection though