Grade passback not working for Muzzylane with LTI 1.1

[ayub02]

I've added a Muzzylane assessment in Ulmo and Master sandbox via LTI 1.1. The tool itself works fine and as a learner, i'm able to attempt the assessment. However the grade passback is not working.

1. Link to Master sandbox
2. Link to Ulmo sandbox

According to devs at Muzzylane, they are encountering 500 error when posting grades back to edX platform. They generated a log file which is attached.

log_snippet.txt

[ayub02]

@navinkarkera found that the issue is not with the tool but with LTI store. On the block configuration for this tool works just fine. I'm closing this issue in favor of this one: #620