I don't understand why this has happened 3 times now in the passed few months, just out of the blue, I get that message, and have to go through a complete re-install. Sonar has been installed, and working correctly for years now.
Talk about a total creativity killer!
Anyone got a clue why this would happen?

Registry corruption?

I was thinking a misbehaving registry cleaner.

It also sounds like it could be a glitch caused by anti-virus or malware software.  I had AVG think part of my installation was malware in the past.