Strange Constant Disconnects From Sponge Forge Server—SkyFactory4

I made a bungeecord(hexacord) network of servers. One was Sky Factory 4. I realized I had to use spongeforge to make it work with bungee cord because I needed IP forwarding or something. The server now works, and I play with my friend. The problem is every few minutes we get disconnected and sent back to the lobby. If we wait about 30 seconds we are able to connect again, it doesn’t crash. It appears that nothing happened on the server side log. On the client side there is a java.lang.IndexOutOfBoundsException error. I’m not sure what is going on, but if it is client side that would be strange because it happens to both players simultaneously.
Here is the part of the client log where we get disconnected: latest.log - Client Side - Pastebin.com

I have been trying to get help with this all week all over the internet. I’ve been sent between a bunch of forums to here. I hope this will be the end of my search for help!

Hello,

I think I’m stuck on the same error. Have you ever found a solution to this?

Greetings