Quote from AtomicStryker
I just checked against my Forge 998 MC, it works.
That did the trick. MCF 10.12.0.991 -- nope. MCF 10.12.0.998 -- yes. Must've been something MCF fixed between versions.
MCF says it wants to see an 'mcmod.info' file in the *.zip ... but there is one right there in the *.zip. Another weirdness about MCF.