Power Apps Calling Flow : solving the “failed during http send request” error

6 months ago when moving an existing Power Platform application from DEV to UAT and as such when switching to a service account for the maker, I’ve faced the infamous error “failed during Http Send request”.

I had a Power Apps application and a Flow starting from the Power Apps trigger.

Here are the repro steps:

A basic flow with a Power Apps trigger and 2 connections:

And when I connect my Power Apps application to the flow, I get this error:

To understand the reason, let’s start the browser developer tools and let’s trace what happens when we add the reference to the flow from Power Apps:

We get an error 403, meaning access to the requested resource is forbidden for some reason. When we click to get the details, we can see that each connection in the Flow generate an error : the connection to Outlook and the connection to Excel:

So this is clearly an annoying bug.

What happens : when the flow has been authored by a user named “sergeluca” the connection have been using the credential of sergeluca.

The flow has been shared with another user1 (co-author). When the co-author user 1 did create the Power Apps application, at design time Power Apps studio noticed that the connections inside are owned by sergeluca and therefore user1 got an error. This should not happen, because when the PowerApps application runs, the current user credentials are applied to the invoked flow connection anyway.

In my opinion this is a bug that complicates the “co-owner scenario” and should be fixed asap.

In the meantime, the workaround is the following: if you create a flow with a service account, use the same service account for binding the Power Apps with the flow. And avoid different credentials in your flows.

I hope this helps