First thing -- when going Prone using Vic's Modern Warfare Mod, this happens:

I think what's happening here is that both mods are attempting to rotate the character model 90 degrees, which results in a kind of hilarious 180 flip.

The crashing issue, however, is when you pull out a firearm from Vic's Modern Warfare Mod, are crawling/prone, and then hit F5 to go into third person. The game just crashes to a grey screen before shutting down entirely.

Here's the crash log from that: https://paste.dimdev.org/izusuqepeb.mccrash

I hope to see these mods working together. :) I love that you backported the 1.13 swimming physics!

Its a incompatibility with our shitty code when it comes to rendering the player. Will be fixed when I have the time

I look forward to when it's fixed so I can re-add it to my modpack. :) Keep up the good work, and thanks for the mod. ^^