Well, sad to say, by doing this cache thingy with steam cs back in February (or was that January?) they totally screwed up making cool plugins like these work.
And to think of, I wonder really why they did this. The so called "performance gain" is probably not there, by going around find_ent_by_string (or whatever they do), or at least it's not likely that it is so big that it has any serious affect on game play.
If you ask me, a total screw up by the CS team.
Don't know if there's any way around this, like finding a way to make steam cs "catch up" with the current entity set. That would be cool, I doubt we'll ever see it

but keep your fingers crossed.
Objectives converter, RIP.