Custom connector returns empty response body when used in canvas app

[BertMuller1968]

Hello,

We run into a strange problem when using a custom connector to a REST API, and we hope anybody here can help us!

A call to the API should return a JSON object, and when we test the custom connector it works fine. The schema is validated correctly, status 200 is returned and the response body contains the object we want.

When we use the connector in a canvas app however, we get the message "The data returned into the response is invalid. Response data should be a valid JSON object."

In the Power Apps Monitor we see that the response body is empty when run it from the app:

"response": {
"duration": 170.35,
"size": 0,
"status": 200,
"headers": {
"Content-Length": 0,
"Date": "Mon, 25 Jan 2021 11:54:11 GMT",
"x-ms-apihub-cached-response": true
},
"body": ""
}

The connection is OK, but the body should not be empty. When run from the Power Apps test environment or from Postman, the desired object is returned without any problems.

The Swagger file from which we constructed the connector is attached to this message.

Would anybody know what we are doing wrong here? Any help is very much appreciated!

[BertMuller1968]

Update: app works when run on phone, but still not when opened in web browser.

[packnology]

Hi @BertMuller1968 did you ever figure out this problem? I'm having exactly the same issue. I notice that if I use the custom connector in a Power Automate flow it works, but it always returns an empty response body in a canvas app, and (unlike your description) is also empty when I use the test function in the custom connector designer.

Thanks,

Greg

[seadude]

Similar issue here. 
- Works in Custom Connector Test tab:

- Does not work in PowerApps

- This Custom Connector returns an plain SVG.

    - Do I need to URL Encode the SVG and pass it to the Custom Connector as JSON?

[aditya281]

Hi, I am facing similar issue.. were you able to figure out the root cause. For me, i get response in power automate but gets blank 200 OK response in canvas app or test tab of custom connector

[NameOfUser]

I saw a similar issue. It ended up expecting an array of JSON objects rather than just a JSON object, even if we only passed it an array of length 1, something like this:

[

    {

        cache-control": no-cache",

        content-encoding": gzip"

        ....

    }

]