Power App Unable to add flow

I was in the process of porting a production Power App to a dev environment, and I ran into this error.

Unable to add flow
There was a problem adding your service. Please try again later.

The problem was that I tried to add an existing Flow to my Power App, but it was turned off.



Navigate to make.powerapps.com, locate the Flow you are trying to add to the Power App, turn it on, then try adding to the app.