LTI Integration set up internal server error

[AsvinPeiris]

We're currently looking at using LTI and integrating with the platform but running into some issues. As far as we can tell, the configuration is correct, but we're getting an internal server error on the Canvas side after the redirect. We've looked at the docs and all the details that are required look to be correct. We're using a cloud hosted Canvas setup. 

The error we're getting is:

{"errors":[{"message":"An error occurred.","error_code":"internal_server_error"}],"error_report_id":3451}

Is there a way for us to see these errors, or is this completely hidden away from us. When we go to `/error_reports/3451` we get a "you don't have permissions to view this" — no one on our systems seems to have permission to view this.

Any help or guidance would be highly appreciated.

[DJLynch]

I'm also running into this issue and it doesn't look like error reports are available via the API. Did you ever figure out what was wrong?

[AsvinPeiris]

Sorry for the late response. 

I believe it was something to do with me not using the correct property. I would make sure to check the properties it's expecting based on the docs. 

[DJLynch]

Not a problem, we ended up working it out. I believe our issue was I was redirecting to

https://{our_institution}.instructure.com/api/lti/authorize_redirect?...

instead of

https://canvas.instructure.com/api/lti/authorize_redirect?...

Hopefully that may help someone down the road!

[83219223]

Please, can you tell me more clearly how you fixed it? 

[DJLynch]

This is the step I'm referring to: https://canvas.instructure.com/doc/api/file.lti_dev_key_config.html#step-2-authentication-request

I realize now that the correct redirect is https://sso.canvaslms.com/api/lti/authorize_redirect. It used to be different. When I was developing our tool, the redirect was supposed to be the "https.//canvas.instructure..." URL I listed above but I was using the URL of the institution I was developing for. But I don't think that would apply to your case since the documentation is now different. Make sure it is a redirect too, and not a standalone request. The link I provided above should have pretty good details on the required parameters. I'm not sure what else to tell you. If you provide more details I might be able to help.

An additional note, the original post talks about not being able to see the error reports that are linked. I talked to Canvas support and they indicated these reports are only for Canvas employees/support and no one besides them will be allowed to view the report.

[83219223]

Thank you very much for the useful information, but it seems I'm encountering another LTI error because I haven't installed redis. But I have installed redis services separately without using redis config in Canvas. I wonder if that's possible?

Log error:

[CANVAS_ERRORS] EXCEPTION LOG
NoMethodError (undefined method `sign' for nil: NilClass

private_key.sign digest, signature_base_string
^^^^^):
/canvas/vendor/bundle/ruby/3.1.0/gems/json-jwt-1.13.0/lib/json/jws.rb:107:in `sign'

[DJLynch]

Ahh, I see. Yeah, I don't know anything about that - sorry! Hope you find some help