RM 2.5.2
dualhotbar: latest
Minecraft version: 1.12.2

dualhotbar.zip

What is the issue?
If it crashes, please provide the .minecraft/logs/latest.log file. If it misbehaves, please explain.

Likely source: https://github.com/RebelKeithy/DualHotbar (that's the source linked for the 1.x version which is GPLv3 according to CF, there's a 2.0.0 version on CF which seems to violate GPL by being ARR and nor having any source links)