Hello!
On one of my machines I got this exception when ran tests in Firefox.
I analyzed this method using Reflector and understood that you search FF installations in the registry.
For some reason under HKEY_LOCAL_MACHINE\SOFTWARE\Mozilla\Mozilla Firefox\ I had two keys: 3.6.13 and 3.6.17.
I fixed the problem by manually deleting 3.6.13 key.
I suggest you to add more sanity checks when analyzing keys!
On one of my machines I got this exception when ran tests in Firefox.
I analyzed this method using Reflector and understood that you search FF installations in the registry.
For some reason under HKEY_LOCAL_MACHINE\SOFTWARE\Mozilla\Mozilla Firefox\ I had two keys: 3.6.13 and 3.6.17.
I fixed the problem by manually deleting 3.6.13 key.
I suggest you to add more sanity checks when analyzing keys!