How to fix Cannot read properties of undefined (reading 'error') from Azure App testing extension while recording and create Test

Sheeba Chandrabose 0 Reputation points
2026-05-27T15:38:59.75+00:00

Facing this problem when I try to use the Azure App testing extension on the edge browser to record and create a test script for my Azure Load Testing service to execute. It manages to capture the requests under a scenario however when I click on Review and create test button end up in Cannot read properties of undefined (reading 'error') as shown.

Screenshot 2026-05-27 160001.png

I have just double checked to ensure its not from my application and this happens even when I to record a random scenarios on a random site as well. Is there anything I am missing at my end to make use of this record feature.

Azure Load Testing
Azure Load Testing

An Azure service that enables developers and testers to generate insights on how to improve the performance, scalability, and capacity usage of their application

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  1. Andrew Taylor - COREZENN 1,390 Reputation points Volunteer Moderator
    2026-05-27T15:51:15.1966667+00:00

    Hi @Sheeba Chandrabose

    Thank for reaching out with me here ta Microsoft Q&A. I understand your issue is with the Azure App testing extension.

    Azure App Testing: "Cannot read properties of undefined (reading 'error')"

    This is almost certainly a client-side extension error: the Azure App Testing extension received an unexpected or missing response (often due to auth/permission issues, network/CORS blocking, or a backend validation response with a different JSON shape) and tried to read .error on an undefined object.

    1. Quick fixes: update Edge + the extension, sign out/sign in, try InPrivate with other extensions disabled, or reinstall the extension.
    2. Capture logs if it still fails: edge://extensions → Developer mode → Inspect views → open Console & Network → reproduce → copy the failing request response body and console stack trace.
    3. Workaround: export a HAR/use JMeter/k6 or create the test via Azure portal/CLI and upload a JMeter (.jmx) if needed.
    I hope this was helpful with your troubleshooting issue. Please mark the answer as "accepted" if you found this helpful and please follow me here on Microsoft Q&A.

Best regards,
Andrew Taylor

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