OK, the first error I'm getting is during the world loading, not any exact things to point out but a bunch of particle effects. Then after, errors are created when opening both GUIs, here they are:

Settings:
[Equipped Weapon Addon] lua/autorun/client/cl_ewa.lua:463: Calling net.Start with unpooled message name! [http://goo.gl/qcx0y]
1. Start - [C]:-1
2. func - lua/autorun/client/cl_ewa.lua:463
3. FillViaFunction - gamemodes/sandbox/gamemode/spawnmenu/controlpanel.lua:100
4. FillViaTable - gamemodes/sandbox/gamemode/spawnmenu/controlpanel.lua:89
5. ActivateTool - lua/includes/modules/spawnmenu.lua:291
6. DoClick - gamemodes/sandbox/gamemode/spawnmenu/toolpanel.lua:80
7. unknown - lua/vgui/dlabel.lua:218

Info:
[Equipped Weapon Addon] lua/autorun/client/cl_ewa.lua:77: attempt to index a nil value
1. func - lua/autorun/client/cl_ewa.lua:77
2. FillViaFunction - gamemodes/sandbox/gamemode/spawnmenu/controlpanel.lua:100
3. FillViaTable - gamemodes/sandbox/gamemode/spawnmenu/controlpanel.lua:89
4. ActivateTool - lua/includes/modules/spawnmenu.lua:291
5. DoClick - gamemodes/sandbox/gamemode/spawnmenu/toolpanel.lua:80
6. unknown - lua/vgui/dlabel.lua:218

The removed link contains this:
util.AddNetworkString( "string" )

@Beefy_Tim: these errors never happend to me , very strange, they happen everytime , or just once on loading ?

I just loaded a map to test it and i crashed

i cant get any code because my game freezes when i load and it crashed right at the movent i got the ability to check

@Omega_Hawk: this addons doesn't cause crashes, only rarely online.
did you activate something from the addon ?

hmm it works now

ok sorry zombie it apears it was just a fluke

@Omega_Hawk: ofcoarse it works ;) , have fun :p

Every time -_-

@Beefy_Tim: very strange, this addon has been test multiple times among friends and on my server, never encountered this addon

let me isolate it, never did that yet.

@Beefy_Tim: great idea

Found the bug during the world load:

[Equipped Weapon Addon] lua/autorun/server/sv_access.lua:42: bad argument #1 to 'JSONToTable' (string expected, got nil)
1. JSONToTable - [C]:-1
2. loadSettings - lua/autorun/server/sv_access.lua:42
3. unknown - lua/autorun/server/sv_access.lua:46

@Beefy_Tim: goto garrysmod/garrysmod/data/ and remove the folder 'ewa' that should fix it , no idea how this bug could have happened