Hello everyone so I am going to keep this brief. Basically, Optifine and Forge are not compatible in 1.13, but they are in 1.14. More Player Models hasn't released for 1.14 officially though so there's a pickle players might find themselves in. I found a work around. Notice: Optifine broke custom item models in 1.14, so MassiveBound will be broken if you use this method. If the server is in 1.15+ this tutorial is useless. Install Forge 1.14.4. Download Optifine 1.14.4 and when the window pops up click Extract instead of Install. Take the Optifine 1.14.4 MOD file and put it in the Mods folder. Be sure you removed all old 1.12.2 mods etc first. Make sure More Player Models hasn't officially released a 1.14.4 version here. If MPM hasn't released an official 1.14.4 version, Use this Snapshot. Install any other Allowed mods that work in 1.14.4 and Profit. Connecting to the 1.13 server with 1.14 is possible and works. I've tested this setup myself. Its the best workaround right now to have Mods AND Optifine, though Custom Item Models will be broken.