In your guest os, find the file %programfiles%\VMware\VMware Tools\plugins\vmsvc\disableGuestHibernate.dll delete it or move it.
Finally, disable hibernation once and for all by opening an administrator elevated command prompts and running:
powercfg -h off
Background:
The disableGuestHibernate plugin loads when vmware tools loads. If vmware tools loads while running in a vm, it will disable hibernation (since vmware has its own suspend system making hibernation redundant.) But if vmware tools loads outside of a vm (i.e. you use boot camp to boot into windows instead) it will re-enable hibernation if its disabled.