I just had a similar case where I could not open the tab for my favorite vms, named "Library". I restored that tab by removing my removing my inventory.vmls and preferenes.ini files. After restarting VMWare Workstation, my "Library" tab was restored. I had to re-open all of my VM images to get them into my favorites list again, but that only took a few minutes.
In comparing the old inventory.vmls and prefernces.ini files to the new ones created, I don't see anything obvious to tell me why the "Library" tab wasn't restarting before though. So I don't have a reason why this works other other than to say that this work around does work.