The application you are using ran into a problem.
If you let their support team know about this error, please give them a link to this web page as well!
Your application is running into a bug in elm-lang/virtual-dom at some point. The root cause may be in your code or in a dependency.
Try to reproduce the issue in dev mode. From there, create an SSCCE that reproduces the issue and report it here with a title like “Implementation bug: ...” and a description that explains your understanding of the problem.
Hopefully that helps!