If you are unable to resume a virtual machine that had been suspended:

1. Navigate to the directory where the virtual machine’s files are located.
2.
Delete the file that ends in .vmss as well as any files or folders that end in .lck.

Note: The suspend state of the virtual machine will be lost. This operation will replicate a physical machine having had its power unplugged.

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1003846