VMware Fusion Error- Found & Fixed!

VMware's Fusion is a terrific way to run Windows on a Mac. I ran into a problem the engineers at VMware hadn't seen before and couldn't fix (yes, we have a direct line to them). In fact, they were leaning towards blaming it on Microsoft-- which may be accurate-- but it was caused by Fusion.

Here are the details:

• Fusion allows you to launch a PC application even when Fusion isn't running by double-clicking on a file type that requires a PC program.
• I tried that on a Microsoft Visio file, and got all sorts of Visio errors that caused my virtual PC to restart. The specific results were that Viso opened slowly, then opened 25-30 windows very quickly, shutting them down just as quickly, then restarted the PC (which is running Vista Ultimate). Opening Visio natively in the virtual PC had the same results. Visio was unavailable-- period.
  
• I tried uninstalling and reinstalling Visio. Same problem. I combed the registry and found nothing. I called VMware, and their programmers said that based on what they do, it must be a Visio problem-- even though the problem started when I tried this new functionality of opening a PC file from the Mac without Fusion running.

I went back to the PC's registry and looked for more clues. Here's what I found:

• I had Visio set to reopen the last file automatically. It was pointing to that same file, whose path it couldn't resolve.
• We map drive letters to point our PCs to various areas on the network. Drive N points to the redirected My Documents folder on the network. The line in the registry that formerly told Visio to start in "n:\" now pointed to "n;\".
• Removing the file from the start line in the registry and fixing the StartIn path resolved the issue.

I called VMware's engineers and let them know so they can put it in their knowledgebase.