Help I have messed up with Fusion

Though there's some information on the VMware website discussion
forums about repairing damaged VMDK disks, I think a lot of it doesn't
apply to Fusion because it is VMware version 6, and a lot of the repair
info is VMware 5 or earlier.

It looks like VMware's official position is that their software will repair
a damaged disk automatically if it can, but sometimes it can't. They
recommend regular backups, just like on a real computer.

They do say that "monolithic" (single large files) VMDKs are the most
difficult to repair, and recommend using split disks as being easier to
repair when required. (So why isn't that the default?)

The only thing I can think of trying is to use the vmware-vdiskmanager
utility to read your damaged VMDK and see if it can make a new
split VMDK from it. The utility is in:

/Library/Application\ Support/VMware\ Fusion\

It's a command line utility and needs to be run in a Terminal window.
The command would be:

vmware-vdiskmanager -r damaged.vmdk -t 1 new_split.vmdk

If it works, then you can either create a new VM that references the
split VMDK, or edit your existing VM's vmx file to reference it.

Good luck.