Felix Griffin's Editor Mod (FGEMOD)
@SjorsMaster:
If the game crashes at the start or while loading a map, there is something wrong or missing
in the 'editoritems.txt' file in your 'script' folder. You can fix this by editing it yourself
or replacing it with a backup or an working one. 
To get the CMD window big, you might have to start it as administrator and change the default settings.
(click on the icon on the top left of the window, change the settings, and restart CMD)
---
about FGEMOD and "saving":
Bee sure to select some items you want to use and dont forget to press [F1] to save it.
It will compile of the items into the 'editoritems.txt' anyway, but only some of them
will be visible ingame then.
Can someone upload some working editoritems.txt?
The FGEMOD.exe won't work.
The FGEMOD.exe won't work.
[spoiler]- BEE2 Addons | (BEE2)
- Hammer Addons
Maps:
- Crushed Gel
- Gel is Not Always Helpful[/spoiler]
Good, but that are the standart items, how can I use the items from FGEMOD, BEEMOD and HMV? When I use the FGEMOD.exe and save, go to portal 2 and make a map I became an error which isn't when I use this editoritems.txt:
Additionally, while I was making this map, the editor unexpectedly sported some one-off bug which allowed me to place glass panels in 45 degree tilted orientations (with major glitches). You can find them as a decorating element in two locations.
Incidentally, something or other that I did resulted in the default placement of light panels being in the center of the square. This allows placing three light panels at even spacing within the same square, which you also see used in this map. If you use the adjustment gizmo, you are then forced into the 4 positions, even if you undo it.
Turns out the vacuum tubes, buggy as they might be currently, make for an excellent decorative element. I used them extensively in this map. I also use them as an actual puzzle element towards the end of the map.
Nowadays I have settled into writing my own editoritems.txt files. I have extended the editoritems*.txt files from Stylesmod to include all the items from FGEMOD as dormant elements, and also unified the light panels, and then just enabled/disabled/replaced some elements in the palette where needed. Sometimes I choose some items in the palette, place them in some corner on the map, save, and then change the palette. Even if the items are no longer in the palette, I can take them from that corner in the map, and move and clone them where I want. For instance, that's what I did with the vacuum tubes in this map.
Here's the editoritems.txt that I used for this map: http://pastebin.com/AKRXZVSs
Oh, and I edited the elevator entrance file to avoid Glados talking about new testing elements and lumps of coal. I found her default speech about momentum much more fitting for this map. Similarly I removed the sphere on sphere receptable speech, because it gets annoying when you hear it the third time (and it belongs to the coop campaign anyway).
(Why am I posting this here? Because I thought it would be interesting to see a practical application of those tubes.)
EDIT: Users are reporting me there are big "ERROR" signs in the map where the tubes should be.
If you are getting the in-game error "failed to build level" then it's the sendificator bug:
Open it with 7Zip, then find the folder inside it called maps/instances_hmw/gadgets. Copy this folder to maps/instances/hmw/gadgets (note the slash between instances and hmw!) and try to build your test again.
Hopefully it will work for you after this. 
If you open the developer console after this error, it'll show you which files are missing and therefore where to put the files and folders.
[spoiler]- BEE2 Addons | (BEE2)
- Hammer Addons
Maps:
- Crushed Gel
- Gel is Not Always Helpful[/spoiler]
And where I get this datas?
vbsp_styles: Saved modified D:SteamsteamappscommonPortal 2sdk_contentmapsstyledpreview.vmf
vbsp_styles: Changed 0 materials.
vbsp_styles: -game "D:/Steam/steamapps/common/Portal 2/portal2/" "D:SteamsteamappscommonPortal 2sdk_contentmapsstyValve Software - vbsp.exe (May 30 2013)
2 threads
materialPath: D:SteamsteamappscommonPortal 2portal2materials
Loading D:SteamsteamappscommonPortal 2sdk_contentmapsstyledpreview.vmf
ConVarRef gpu_level doesn't point to an existing ConVar
Could not open instance file instances/hmw/gadgets/sendtor_manager.vmf
This file is missing, which stops the compile. You need to download the source for the sendificator, and install it's files.
[spoiler]- BEE2 Addons | (BEE2)
- Hammer Addons
Maps:
- Crushed Gel
- Gel is Not Always Helpful[/spoiler]
Okay, thanks, it works!
But, I have an another question, can I use FGEMOD with Style Changer?
When yes, how?
Since I installed this it wont rebuild. Also the first time I used it I stupidly selected them all but now when I just select specific ones it still Adds them all?
Any Help is much appreciated. I have BEEMOD, HMW, and StyleChanger installed from a while back does this affect it?