Felix Griffin's Editor Mod (FGEMOD)
Hm. That's REALLY weird. Could you check if you have write permission on that file? Also, what did the FGEMOD say right before it closed? (It should be "Done. Press any key to exit." or some such.)
Did you quit and restart the game?
Can you perhaps make a version of the editor that's more graphic (i.e it doesn't run through a console) and also allows you to select whose voice appears in the rooms you create (Cave Johnson, GlaDOS, or silent.)
Breakable glass seems to be rather problematic.
First of all, it's centered in the voxel, contrary to normal glass which is on the edge. This makes it difficult to use it in meaningful ways, such as to form breakable enclosures.
Secondly, the glass appears to be one-sided: You can see the surface from only one side. From the other side, it looks like there is no glass. EDIT: Not true. Just really hard to see depending on lighting conditions.
Thirdly, orientation of the glass seems to be completely random, and varies depending on other elements you have in the puzzle.
Fourthly, whether turrets can break the glass when they shoot at it, appears to depend on unknown factors. It sometimes works from one side only, sometimes from the other.
And fifthly, the glass is not extensible. You can't extend it like you can with the regular glass and with the grating.
Is there a fix to (some of) these problems?
Answers in no particular order:
I'm not able to make the glass extensible, unfortunately, because that's hardcoded into the editor. Carl might have a way, using the modified compiler, so I'll ask him.
The orientation should be fixed (perpindicular to the edge of the handle), but it's completely counterintuitive. I'm making a new editor model.
Good idea, I'll move it to the edge.
Could you post a video of the turret glitch? If I tip a turret and aim it at the glass it will break from either side, so I want to see what other things you have that might affect it.
Tl;dr: I'll fix as many of those as I can. 
The turret glitch was probably caused by having the turret aim too well. Was I was trying was standing in between the panel and the turret. It seems to be a mistaken report by me.
Re: The edge, you'd probably do best by using the same alignment model as is used for fizzlers and for Ben's door, if possible... Btw, Ben's door doesn't block excursion funnels when closed. You probably can efficiently pass this bug report forward.
I can, that was actually a glitch in the original Portal 2 that made it into the PTI. It was fixed after a couple months with an interesting log (Fixed: tbeams getting in under the door and leeching off your skin). I don't know why, but they didn't make the door become truly solid when closed.
The portal deflector cube... How is that supposed to work? Is it confirmed to work? I can't get it working. It appears just fine, looking like a lens cube with red tesla effects inside, but when I shoot at it, the effect is exactly the same as when shooting at any other cube, i.e. portal won't connect.
What I do see is that when the cube is standing on a floor, and I try to put a portal _underneath_ the cube, the portal is bumped on the floor. This also happens sometimes on the walls. What could there possibly be a use for this effect?
Interestingly, the cube is unaffected by both a laser and a Combine energy ball. It is properly fizzled though.
I don't think the global ents are in the FGEMOD, but the effects are shown in my (unfortunately glitchy) map Forcefields and Cubes. When you shoot a portal at it it deflects the portal. If you play this map you have to cheat and give yourself a portalgun or it will be unbeatable, just a word of warning. FelixGriffin's Contest Entry - Forcefields and Cubes