1101 Error

A 1101 Rendering error is a Cloudflare-specific error code for:

"There's a Javascript issue."

Common cause

A Cloudflare Worker throws a runtime JavaScript exception.

Resolution:

The Cloudflare administrator will need to provide appropriate issues details to Cloudflare Support.

Source: https://support.cloudflare.com/hc/en-us/articles/360029779472-Troubleshooting-Cloudflare-1XXX-errors#error1101