i have just downloaded the latest versions of my different mods and it seems that minecraft crashes because of randompatches. I have removed the mod and minecraft doesn't crash.
log: https://pastebin.com/DmaiyTJd

Does the crash occur consistently?

apparently not. Why does this not happen consistently?

I have tried it now multiple times and it didn't crash just the first 2 times today, then i removed it and reported the issue. Now it doesn't crash. Does that make sense according to the log?

Yeah, the class loader is trying to generate metadata for a class, and in doing so, concurrent modification of the metadata cache occurs. I have no idea why this crash would be occurring, and I'm not sure if it's specific to my mod. If you can find a way to consistently reproduce it, let me know. 😄

Ok, i will close this for now