Just recently with the announcement of Win 10 made available for free, I wanted to upgrade, but got an error message that I can not upgrade due to SVGA drivers compatibility. Between VMware and Microsoft, they are both pointing fingers to one another and nobody wants to take responsibility. So, the easiest way to do it, would be to download the ISO and perform the upgrade yourself.
Here is the direct link -> https://www.microsoft.com/en-us/software-download/windows10ISO.
Source:
http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1011709
https://communities.vmware.com/message/2523524
http://www.imore.com/how-avoid-windows-10-upgrade-problems-vmware-fusion