After using omnifs32.exe to manipulate a VMWare VMDK file, you receive the above error message when you try to power on that virtual machine.

 

This issue occurs if you try to manipulate the filesystem of a VMDK for which there is an associated VMWare snapshot.

Omnifs32.exe is not supported and not capable of manipulating the filesystem of a VMDKs that contain snapshots. Once this error message occurs, you will have to revert to a known good snapshot to resolve the problem. If you want to use Omnifs32.exe on that VMDK without receiving the error, the snapshots must be removed.