FACT CHECK #FANFKT-_

WHAT WE FOUND

The occurrence of 'Invalid Token' errors during API queries is a well-documented technical fact across multiple software platforms 3 5 20. Common causes for these error responses include signature key mismatches, missing audience claims, and untrusted key IDs 1 5 7. Technical guides published in early 2026 detail how to diagnose OAuth2 invalid token errors by focusing on audience validation and signature integrity 8. Specific instances of these errors have been verified in Zoom user-managed apps, ArcGIS REST APIs, and Microsoft Power BI 3 19 20. Developers typically encounter the invalid_token status during testing when a signature key is not found or when a token is signed by an untrusted key 5 7.

SOURCES

1. 1 · community.auth0.comACADEMIC
   JWT token is "invalid signature"? - Auth0 Community

   TIER A

2. 2 · arxiv.orgFACT-CHECKER
   Building, Benchmarking Customized Fact-Checking Systems ... - arXiv

   TIER A

3. 3 · devforum.zoom.usWEB
   {"reason":"Invalid Token!","error":"invalid_request"}

   TIER B

4. 4 · pmc.ncbi.nlm.nih.govFACT-CHECKER
   The perils and promises of fact-checking with large language models

   TIER A

5. 5 · stackoverflow.comACADEMIC
   Bearer error - invalid_token - The signature key was not found

   TIER A

6. 6 · firebase.google.comWEB
   Verify App Check tokens from a custom backend - Firebase - Google

   TIER B

7. 7 · github.comWEB
   INFO[0101] failed to verify token: token signed by untrusted key with ID

   TIER B

8. 8 · oneuptime.comWEB
   How to Fix 'Invalid Token' OAuth2 Errors - OneUptime

   TIER B

9. 9 · googleapis.github.ioFACT-CHECKER
   claims() - Google APIs

   TIER A

10. 10 · aclanthology.orgFACT-CHECKER
    [PDF] FIRE: Fact-checking with Iterative Retrieval and Verification

    TIER A

11. 11 · reuters.comFACT-CHECKER
    Reuters Fact Check

    TIER A

12. 12 · toolbox.google.comFACT-CHECKER
    Fact Check Tools - Google

    TIER A

13. 13 · reutersinstitute.politics.ox.ac…NEWS
    How the public checks information it thinks might be wrong

    TIER A

14. 14 · misinforeview.hks.harvard.eduFACT-CHECKER
    “Fact-checking” fact checkers: A data-driven approach

    TIER A

15. 15 · factcheck.orgFACT-CHECKER
    FactCheck.org - A Project of The Annenberg Public Policy Center

    TIER A

16. 16 · apnews.comFACT-CHECKER
    AP Fact Check - AP News

    TIER A

17. 17 · libguides.rowan.eduFACT-CHECKER
    News Literacy Toolkit: Fact Checking - Research Guides

    TIER A

18. 18 · ballotpedia.orgFACT-CHECKER
    The methodologies of fact-checking - Ballotpedia

    TIER A

19. 19 · community.fabric.microsoft.comWEB
    Re: Service Returned an Invalid Token - Microsoft Fabric Community

    TIER B

20. 20 · community.esri.comWEB
    ArcGIS Server 'Invalid Token' from application, using REST API

    TIER B