Hi Josh:

It's interesting you find it is an intermittent issue. We had some very large rules and when we turned on the new rule editor no matter what would get an :( face. 

If we deleted a few rules up to a certain amount this would load up correctly. 

If you look in your devtools when this happens it is a timeout issue where the connection is being closed prior to the rule having loaded. 

With asking WRC and pointing out the issue the :( issue was replicated in 2023.1 but did not happen in 2024.x. 

What I think it is is the gateway timeout time is too small and if you update the timeout to a bit longer it might allow the web application to load. 

Alternatively go to web application /ui/interop/rule-editor and disable the application to go back to the old rule editor. This issue and No crtl+f find functionality has caused many people to divert from the new editor until it is optimised, as well as i believe in 2023 too much whitespace.