Troubleshooting
Every message below is the exact text PrepareBuddy shows. Administrators can see each grade delivery, with the LMS's reply, under Recent gradebook deliveries on /lti/manage/.
Launch messages
| Message | Cause | Fix |
|---|---|---|
| The launch signature is not valid. | LTI 1.1: the consumer key or shared secret in the LMS does not match PrepareBuddy. | Re-copy both from /lti/manage/. If you generated a New secret, the LMS must be updated. |
| This LMS connection is not recognised or has been turned off. | LTI 1.1: unknown key, or the key is turned off. | Check the key on /lti/manage/ and turn it on. |
| The launch has expired. | LTI 1.1: the LMS server clock differs from real time by more than 5 minutes, or the page was reopened from history. | Open the link again; if it persists, ask the LMS host to fix the server clock (NTP). |
| This launch was already used. | The same launch was submitted twice (back button, refresh). | Open the link again from the LMS. |
| Launch validation failed: … | LTI 1.3: the details registered on /lti/manage/ do not match the LMS (issuer, client ID, keyset URL, deployment ID), or the LMS clock is wrong. |
Compare each field with the LMS's tool details. Unknown deployment_id → add that deployment ID. |
| Unknown LTI platform / Ambiguous LTI platform | LTI 1.3: no active registration for this issuer, or several share it and the LMS did not send a client ID. | Register the LMS on /lti/manage/ with its exact issuer and client ID. |
| This launch expired or was already used. | LTI 1.3: more than 10 minutes between login and launch, or a replay. | Open the link again. |
| This LMS connection is not attached to a PrepareBuddy organization yet | An LTI 1.1 key without an organization (created before this version). | Create a new key on /lti/manage/ for the organization. |
| The test / quiz / assessment this link points to (id …) is not available to … | The link names something that does not exist or does not belong to your organization. | Re-add it with the picker, or copy a link from /lti/manage/. |
| Your email belongs to a PrepareBuddy account that cannot be opened from an LMS. | The email belongs to a PrepareBuddy staff account. | Use a separate student/teacher account in the LMS. |
| Your email is already used by a PrepareBuddy account at another organization. | The student's existing account belongs to another institution. | Add that account to your organization in PrepareBuddy, then open the link again. |
| More than one PrepareBuddy account uses your email address. | Duplicate accounts. | Contact support@preparebuddy.com. |
| Your access to … has been turned off. | The student's membership was deactivated in PrepareBuddy. | Reactivate it, if intended. |
| Your LMS did not send a user id. | The LMS tool settings withhold user information. | Enable sharing of user identity with the tool. |
The tool shows a blank area inside the LMS
PrepareBuddy's launch card is allowed inside LMS frames. A blank frame usually means a browser extension or a strict school network policy is blocking third-party content. Set the link to open in a new tab/window (recommended anyway).
"Open PrepareBuddy" does nothing
The browser blocked the new tab. Allow pop-ups for the LMS's site, or set the link to open in a new tab.
The student lands on a sign-in page
They opened a copied link instead of the LMS assignment, or their one-time sign-in link expired (10 minutes). Open the assignment from the LMS again.
Grades
| What you see | Meaning | Fix |
|---|---|---|
| Sending… | Queued, or the LMS was unreachable; retried automatically (1, 2, 4, 8, 16, 32, 60, 60 minutes). | Wait; check the LMS is up. |
| Failed with an LMS message | The LMS refused the grade — e.g. the student has left the course, the assignment is not graded, or (LTI 1.3) grade services are not enabled for the tool. | Fix the cause in the LMS, then Resend. |
| Not sent after the student finished | A test result is held for teacher review or has no overall score yet, assessment feedback has not been released, or the link has no gradebook column. | Release the result or feedback / wait for grading / make the assignment graded. |
| Grade shows e.g. 83.33 instead of 7.5 | Points possible is 100, not the maximum. | Set points possible to the maximum (Scores and the Gradebook). |
Getting help
Email support@preparebuddy.com with your LMS and version, the LMS link (assignment) name, the time it happened, and the exact message. Administrators can include the delivery row from /lti/manage/.