This recently happened to me as well. This thread was a help. Thank you.
Thank you! I had this issue with a model I made on my computer that I've never used dual monitors with, and this worked!
Thanks for posting this. I have one user out of a group who has this occur when he tries to open a particular model in edit mode. It's a strange problem, but it's good to have a simple fix..
THANK YOU. That was maddening.