External display wont work when I close MBP lid after updating to 10.10.2.. Monitor shows message "Not Support".
So I have a mid 2009 MBP 13-inch, 2.26GHz, 8G memory, 10.10.2 with an external monitor plugged into the thunderbolt. Dual monitor works fine when mirroring and also using them separately. Before updating OS I could close the lid and the external monitor would work flawlessly. One day I plugged in my comp and closed the lid and my monitor when black with the message "Not Support". I do not remember changing any setting to cause this. I have read read many discussions and have not found anyone with a similar issue. I have everything needed for using an external display (power, keyboard, mouse...)
I will also add that on the user log in screen, I can have the lid closed and my monitor will independently display the login screen. Once I type in my password, The screen goes blank with the "Not Support" message.
What do you think could be the cause of this annoyance?
MacBook Pro, OS X Yosemite (10.10.2)