Also I can not Change Page Title and Name on "Page Management" when the page is Disable, I have to UnCheck Disable (Change back to Enable) and then Change Page Name and Tile, and Again Change page to Disable.!!!! Before I could change name and tile it directly from Page management.
And Also
I can not Change "Page Title" and "Page URL" in Same time... because I got same Error. I have to change Page name in first Step and Keep URL same old (For example: /Activity-Feed/My-Profile-en-US" and after sav changes, I come back to Page setting and Again Change Old URL "/Activity-Feed/My-Profile-en-US" to New URL "/Activity-Feed/My-Profile"... before has been change Several things together and one time Click on Update... Now It's impossible and you will got that error