I was debugging a C# application in VS2015 and needed to analyse a 3rd party DLL issue. I have a .NET Reflector license and attempted to generate PDBs. Reflector forced me to set DEVPATH to access the Regenerate PDB feature. In doing so, my application stopped working and several Windows services stopped and would not start.
The root service that didn't start (others were dependent on) was the Net Tcp Port Sharing service.
As our application depends on IIS hosted web services, our application became non-functional.
I'm posting this as informational for others who encounter this issue as I have worked out what Reflector did and why things fell over.