Already just reported that the same problem has happened to me.
Have now played Oakmont in single player SP and after the 5th hole once again this same error message appeared. Had to totally reboot the computer to get back into the game, VERY FRUSTRATED NOW!
I have never come across this problem until today. What is going wrong with this game at the moment. We seem to be beset by problems and glitches most of the time. You do not seem to be able play the game in any form without experiencing GREMLINS.
Before some bright sparks suggests it, my cache etc are cleared on a regular basis. There is NOTHING wrong with my PC.
Think its time we had some explanations and answers from WGT as to the causes instead of the total silence we experience!!!