how come the grenade only tag doesn't work? (at least with stick 'nades) and checking bazooka only causes an error when the actual wall is shot? + The bazooka + nade option only allows for bazooka shots to penetrate? Is there going to be a fix for this any time soon?

this is a problem on your end. bazooka flag works perfect for me.
try getting the fgd again or just taking a look at it.

I'm using AngryBeaver's updated fgd...maybe it's just a glitch in there. But I've heard of other people getting the error too...

Well I tested the entity to death and all I have to say is

Grenades dont blow up walls unless guns can aswell.
My .fgd version works fine with no error messages when It's blown up or cxertian flags are checked.

hm, it isn't a big big deal, but there's something fishy that's for sure.