Apart from the Reactor Fuel tab being present with Cyanite, all of the JER tabs seem to be AWOL.

Mod versions: forge-1.12.2-14.23.5.2768, zerocore-1.12.2-0.1.2.8, jei_1.12.2-4.15.0.268, ExtremeReactors-1.12.2-0.4.5.65, JustEnoughReactors-1.12.2-1.1.3.61.

Platform: openjdk 8u212-b01-1 on Debian stretch, amd64.

See also debug.log. I'm suspicious of the "Unable to lookup..." errors, but you will know better than I.

Alright, sorry for the late response. From the looks of it, the version of JEI I used for it is too old.

And sorry for it being so late. Live got me busy...

I can't seem to replicate that issue. The logs say nothing...

Try clicking on the box that says crafting in your screenshots. That should show all categories.

Yes, all three tabs show up in the "all recipes" list:

But don't show up when viewing recipes for a specific item:

Above screenshots generated from a minimal pack with forge-1.12.2-14.23.5.2768, jei_1.12.2-4.15.0.268, zerocore-1.12.2-0.1.2.8, ExtremeReactors-1.12.2-0.4.5.65, JustEnoughReactors-1.12.2-1.1.3.61.

That’s because in the example you pressed R for recipe. Try U for usage.