Versions

Minecraft Version: 1.12.2
Silent Gear Version: 0.1.0
Silent Lib Version: 3.0.1

The Issue

Silent Gear may be interfering with crafting in some cases. Seems to be limited to recipes containing only a single item which Silent Gear considers a main material. For example, iron bars and wooden slabs are uncraftable in some cases.
Currently, I can reproduce this in Refined Storage's crafting grid, but vanilla crafting tables and RFTools' storage scanner are fine for most recipes (aside from some random things being uncraftable, but I believe that's unrelated).
My first guess is blueprint recipes are not being matched correctly by some inventories. Will require debugging in my development environment to determine the cause.