Moodle and Canvas grade Passback

by Niranjan eAbyas.  

Hi,

I am using the LTI Provider in Moodle2.9 to integrate with Canvas LMS. Successfull authentication is happening and users are able to take quiz activity in Moodle.

But grades are not passing back to Canvas, I am getting "Error while processing content unencoding: invalid block" when cron is executed. 

Please help me out in finding the cause of the issue. 

Thank You..