Like many, I'm constantly having issues with the infuser. Either a block was wrong when I built it, or a bucket of starlight is missing and I can't see it, or (like now) neither of those is the issue and I'm banging my head on the table.

I'd suggest a nice little red particle effect from the infuser that floats over to the offending error and a nice message as well as to the reason. Like float to the missing starlight, and print "More liquid is needed" or the wrong bit of marble and "Marble arch is missing"

There's already a new tool coming with the 1.9 update that will show errors in the multiblock construction.