"Error! Unexpected failure trying to fetch apis, try again later." Under Application Quick Start

We have two identical machine-to-machine Auth0 applications which are both registered with our API, but one of them has stopped working.

Opening the application in the Auth0 dashboard and navigating to “Quick Start” results in an error pop-up. This leads us to suspect that there is an issue on the Auth0 side.


Furthermore, calling our API with the credentials for this application returns the following error:

{"error":"server_error","error_description":"Script generated an unhandled asynchronous exception."}

Lastly, looking at the Auth0 logs shows a “Failed Exchange” error with the following description:

ExtensibilityImplementationError on credentials-exchange: Script generated an unhandled asynchronous exception.

Not sure when this issue first started, but it was first noticed yesterday and it wasn’t an issue 3 weeks ago when this application was for sure last tested. The fact that the Auth0 dashboard cannot properly display this application makes it seem like this is more than just a configuration issue. What might cause an application to get into this state?

Any help would be much appreciated.

I was able to “fix” this but I’m using the term “fix” very loosely.

I created a new m2m application identical to the one that was giving us trouble and experienced the same issue.

I noticed that the only difference between the problematic application and the working one were that the working one has a metadata field. I added this field to the problematic application and the issue went away. However, it continued to work after I went back and removed that metadata field. Furthermore it didn’t matter which metadata field I added, it didn’t necessarily need to be the same one as the working application.

Though I’ve gotten past the issue any insight on the behavior I’m seeing would be much appreciated.