DarkServerUK Forum

The recent bug where the GUI for NEI disappears and cannot be accessed in the Technofirma modpack has been fixed by several people the following way:

1) open the folder containing the jar files for your client for technofirma (with the pack selected in the ftb launcher go to edit pack, then open folder) and locate the the NotEnoughItems-1.7.10-1.0.3.74-universal.jar and CodeChickenCore-1.7.10-1.0.4.29-universal.jar.

2) download replacements from the internet, they MUST BE THE SAME FILE, newer versions will not inherently work as they are not the default with this pack.
Links:
http://www.curse.com/mc-mods/minecraft/2...re/2218664
http://www.curse.com/mc-mods/minecraft/2...ms/2222998

3) delete the originals installed with the pack by default and replace with the fresh downloads

4) start up your client and first create and enter a fresh single player world to verify this has fixed NEI

5) should now be fixed for multiplayer use

if issues continue there is another fix found by another player, ask in-game about it if necessary.
-Bear

An ide from oxylyus which i think causes the issue:

CodeChickenLib is a mod library required in order for ChickenBones mods to work, with the exception of Forge Multipart. It is automatically downloaded by CodeChickenCore, in .minecraft/mods/<version>, where <version> is the Minecraft version. CodeChickenLib contains common code and libraries needed in ChickenBones' mods. It is required for NEI,

I did your method, Big_Bear91, and it worked for a session, but then NEI turned off the next time I played. Dex mentioned an NEI fix will be coming with next update, so hopefully that puts this issue in the past.
dutchcook- I wish I could translate that into a fix, but i'm not that savvy.

EDIT: to deal with NEI still blinking out after the fix, I just use the FTB launcher to disable NEI universal and Chickencore universal, launch (it will fail), then enable them again, go to single player world, and then back out and connect to the server. and NEI is back. 

Yeah, i am able to turn NEI on by launching client fresh, going directly to a SP world and seeing NEI working, and then switching to multiplayer.

this step is included in your version, so it would prove a false-positive unless yours is permanently fixed after re-launching...

so i am not sure this is required--i didn't touch jars but this workaround works every time for me.