Failed to process deep linking response

Hi all, I am a developer of a LTI tool provider. I have created a new external learning tool with LTI 1.3 and used the tool to launch our tool, but when I send a deep linking response back to Brightspace, I get an error saying the JWT is invalid.

I have checked the LTI 1.3 spec again and I can confirm the JWT has all the required claims and `kid` is in the header.

In the System Log page, I can see many logs about this error, the they do not tell me why the JWT is invalid. For example, in log `#49641854298852801919166365830573535949445044843751407730.0`, the log just says "Error processing deep linking return".


And lastly, this is how the JWT looks like.

Header:
{
"kid": "46492169-27ad-4f99-a233-9cb0a444529e",
"typ": "JWT",
"alg": "RS256"
}

Payload:
{
"aud": "https://edalex.d2l-partners.brightspace.com",
"https://purl.imsglobal.org/spec/lti/claim/message_type": "LtiDeepLinkingResponse",
"nbf": 1687908969,
"https://purl.imsglobal.org/spec/lti/claim/deployment_id": "03859e2a-49bb-45c8-94ed-fb1890bba5b5",
"azp": "fb926228-6667-4b91-bd36-51beaffa9b64",
"https://purl.imsglobal.org/spec/lti/claim/version": "1.3.0",
"https://purl.imsglobal.org/spec/lti-dl/claim/content_items": [],
"iss": "fb926228-6667-4b91-bd36-51beaffa9b64",
"exp": 1687909029,
"iat": 1687908969,
"nonce": "a00066b488a81d8f2d858dc05f93e889",
"https://purl.imsglobal.org/spec/lti-dl/claim/data": "4p1G5bwfmknF1UIhjpn-DpNgVvUCmVh7uSJ7xmB9HbQ~"
}

Any comment or idea is appreciated!!!

Answers