Thanks for the reply Rokas, I was testing RailClonePro404b.
I just tried the recommended compatibility method using maxscript $.railclone.resetCreatedVersion()
however my models do not revert correctly, I am also experiencing many crashes with these setups. I think ill stick with RC331 for now as these were quite elaborate setups and took me lots of time to build correctly
using the old system - The windows I created were extremely versatile and allowed for added mullions, sliding windows, any size spline, many splines etc. I show this in the last 30 seconds of this video https://youtu.be/Xo8RuLjLPYY?t=606
Moving forward though it looks like I will eventually have to update these based on the info you have provided - hoping it will be an easier transition than I am imagining lol.
edit: Hopefully though it could be backwards compatible so I dont have to re create some of my current libraries - and just re create new ones using the RC4 system. Just a hope and dream