For some reason when I try logging on DMU. It keeps disconnecting me. Is it a glitch?  

Same issue (I know thats much help)... 

I've even got the latest Forge version like everyone's saying to get

perhaps you might have to use 14.23.5.2857 forge(?)

You need to update your version of forge to 14.23.5.2857 or higher

It can be downloaded from here: https://files.minecraftforge.net/net/minecraftforge/forge/index_1.12.2.html

Ah okay. Thanks!