• The mod is extremely normal (at least for this matter).
  
• A very small minority of people had experienced.
  
• Just guessing, the mod in your PC missed out some files for some reason.
  
• Or your system disabled to read the script.
  
• Can't find the true reason because no one of these people had co-operated ever.

First of all,
Try mod I uploaded at Klei:Download page[forums.kleientertainment.com]

If it wasn't works too and
you think Gunfire (or something involved) causes crash,

- Go in game->mods, Click "Configure Mod" (of this mod)

1. Off "Gunfire effect" and try to gun shoot.
If the mod works at that time,
either Gunfire effect's prefab must have been missed
or your system disabled to reading the script.

2. Off "Blood effect" and try to gun shoot.
If the mod works at that time,
either Blood effect's prefab must have been missed
or your system disabled to reading the script.