Versions 1.12.2 Combustive Fishing:

• Forge: 1.12.2-14.2.3.5.2825

Observed Behavior: Cant make the blazing rod

Expected Behavior: The blazing rod should be made

Steps to Reproduce:

1. Combining all the materials in the crafting table gives me nothing

You're on 1.12.2, so you need to make the Golden Rod instead. It's down in the description on the Curse page, under "1.12.x Overview".