Versions (Be specific, do not write "latest"):

• Construct's Armory: 1.12.2-1.2.3.4
• Tinkers' Construct: TConstruct-1.12.2-2.12.0.135
• Mantle: Mantle-1.12-1.3.3.49.
• Forge: 14.23.5.2836
• Tinkers Defense: tinkersdefense-1.4.2.25.1

Observed Behavior:

Conarm causes incompatibiliti with tinkers defense. (or viceversa)

crash-2019-04-27_23.30.33-client.txt

I believe Tinkers' Defense/Compendium has fixed this in their 1.4.2.26.1 version.

Its fixed.