O.P. Plus for Messenger 2012 not compatible with Nvidia again
Messenger Plus! for Windows Live Messenger 2012 appears to be incompatible with the latest drivers from Nvidia again. (The August 28th driver and possibly a little older)
Once I reverted back to a driver from July 2013, plus started working again.
This was a frustrating thing to determine the cause of.
Hopefully, the messenger plus team will issue a patch to fix this soon.
Note that this posting may be the first they are hearing of this, and that I am also using MSNReviver to block the required downgrade to Skype!