All of this was working fine (although I'm not sure what the previous resolution setting was at). Then I upgraded to AMD 15.7 and restarted my pc. I received a message that the Input signal was out of range and to change to 1600x900. The screens are all black except for this message. I unplugged 2 screens and was able to get one screen to work properly. Then I extended a second screen but cannot get the third screen back.
Also I tried to reinstall the old AMD driver but this did not help any.