Unhandled Promise Rejection

I am getting the following error in the browser console:

Identifying the source of this error is beyond my expertise. I do not notice any error or misbehavior of my app.

Thanks.

How can we reproduce the error?
Does it show up on a specific page?
What is the URL of the page?
What should be done on the page by the user to see the error?

Good evening, Mark.

The error occurs on this page: https://toughbear.backendless.app/api/files/ui-builder/containers/default/index.html?page=Inspections

Just load the page. The error appears in the console.

When I go to the Logic section of the Page I see the following:

Looks like there is a problem with the logic in the On Page Enter handler. It appears to be something was removed as a Repeater, but the logic was not cleaned up.

That is the source of the error. How would I be able to discover that on my own?

Clicking the first link in the error trace opened the generated source that had additional clues for where the error was.