Fixed error "_gedit_app_get_window_in_viewport: assertion `GEDIT_IS_WINDOW (window)' failed"

On Ubuntu when I try to open a file through gedit, I get following error:

"** (gedit:2679): CRITICAL **: _gedit_app_get_window_in_viewport: assertion `GEDIT_IS_WINDOW (window)' failed"


To fix the problem first remove gedit by command:
- sudo apt-get remove gedit

Then install gedit again:
- sudo apt-get install gedit