• 1.15.2
  -1.90.0 and 1.90.2

##IMPORTANT: I had two other mods on when trying to load this one, so ignore things like that. I am also playing on a Mac, if that messes things up.

• Other Mods (potentially error sources):
  LeopardCraft (my own mod, which you probably didn't know about until now)
  SecurityCraft (you might've heard about this, and maybe you've played it)

• Bug Notes: Happens in common_event phase,
  bug appears to be a missing method in the proxies and network handlers for the mod.

• Notes: I have played this mod for 1.12.2, and it worked fine. So it might be local to 1.15.2 versions.

-Logs:
I have attached both the latest.log and debug.log files, in case you need to look at both:
debug.log
latest.log

Also, this mod is amazing, keep up the good work.

Thanks for the report! Can you include logs and a crash report please? It's very hard to determine which method is not found without any additional information :).

Sure. Here they are:
debug.log
latest.log

If that doesn't work. I don't know what will.

Note: That will provide a download.

Are you sure those are the correct logs? Neither of them appear to include the crash you've mentioned.

It did not crash. Keep that in mind.

Right, OK. However, the error doesn't appear to occur in these logs - I can't see any trace of NoSuchMethodError within them.

Looks like that log was overwritten. I'll get the right ones to you tomorrow.

I had been playing my redstone testing world.

I've got the new logs and a quick note: my forge version was 31.1.14, if that helps.

debug.log
latest.log

Also, just a quick reminder, I have SecurityCraft and my own mod, LeopardCraft on. Also, LeopardCraft is in progress, so if you see errors like missing model for something, that is probably why.

Right - it appears we were missing a version constraint inside mods.toml. We require a later version of Forge than you're using, but I'd failed to declare that. Updating to 31.1.41 (or later) should resolve this.