Same LTI URL, two courses, one works, the other "couldn't find valid settings for this link"

[JeffWillden]

I've seen other posts where they entered a bad URL, but I have a situation where it's the exact same URL to an external tool. The URL includes a resource-ID like https://server/lti/test?id=123 and the Developer Key for the app is configured at the account. It also shows up in the Settings -> Apps -> View App Configurations of both courses as expected. I entered the same URL into an external tool assignment in two different courses, both under that account. And in one course, the link works fine. In the other, it says it "couldn't find valid settings for this link". I'm perplexed.

[mzimmerman]

Hi @JeffWillden 

Just a thought, but does the remote resource that the LTI is linking to require course-level settings or configuration on the remote service?  I.e., linking to a publisher site that requires a "course" to be created on the site before it can be linked from Canvas?

[JeffWillden]

It does not make any requirements of what is created on the Canvas side. It uses a simple link to a remote resource only.

[mzimmerman]

Hi @JeffWillden 

How does the remote server use the "test?id=123" value?

[JeffWillden]

It uses the id number to retrieve the intended resource and present it to the user. Naturally this only happens if Canvas initiates the LTI connection to the external server. On the assignment where it cannot find valid settings, it never initiates the connection.