VMware Guest API is not enabled on the host?

Hi all

For some Windows 2008 R2 VMs we copy from vSphere to Workstation, we've noticed the following errors in event viewer (as two separate events). Any thoughts on whats causing this?

Unable to start "vmGuestLibrary". Error: "VMware Guest API is not enabled on the host" (3).

The "vmStatsProvider" can not be initialized. "vmGuestLib" returns error "VMware Guest API is not enabled on the host" (3).

Thanks!