Error in upgrading 1.7.2 to 1.7.9

got this error when i tried upgrading 1.7.2 to 1.7.9

Could you please confirm for me that you’ve followed all the up;grading steps described here - http://xibo.org.uk/manual/en/release_notes_1.7.9.html

Then when you navigated to your cms address it did redirect you to upgrade page automatically?

yes ,
I Did the same.