Hi,
From the screenshots and the details, you shared, the error “Response is not in JSON format” can sometimes occur when the connector request is not authorized correctly and the service returns a non-JSON response (for example an authentication or permission error page).
For Azure Queue Storage, it is important to note that there are two types of permissions:
• Management plane roles (like Storage Contributor)
• Data plane roles (required to read/write queue messages)
When using Entra ID authentication with Azure Queues, the connector typically requires the Storage Queue Data Contributor role on the storage account or queue resource.
You may want to check the following:
1️⃣ In Azure Portal → Storage Account → Access control (IAM)
Ensure the user or service principal has Storage Queue Data Contributor assigned.
2️⃣ Confirm the queue endpoint is accessible and not restricted by network rules or firewall settings.
3️⃣ After updating permissions, try re-creating the connection in Power Automate / Power Apps, as sometimes the connector caches the previous authentication attempt.
The reason this matter is that connectors in Power Platform expect the service response in JSON format, and if the request is not authorized correctly the service may return a different response format which causes this parsing error.
If you are able to test again after assigning the Storage Queue Data Contributor role, it would be interesting to see if the connection succeeds.
Hope this helps.