Disable all your addons except ReDead, it's probably something conflicting.

I disable all of my addon except Redead in my server or in my computer ?

When your on the GMod main menu go into Addons and click disable all, then find ReDead in your addons and click enable, that's what I do everytime. If you absolutely want to play ReDead with another mod you can go enable that one too, it probably won't conflict. For ex: I enable ReDead along with GMod Legs3 and Hit Numbers addon.

Doesn't work ..

I have just one addon and thats redead and this lua error appear

And man that's a problem on my server not in my computer , all of the player in my server have this lua error

I tryed hosting this on my server once but was never able too. I extracted the addon with GMAD but where to put all the files?

Maybe find a guide on how to host ReDead?

[ReDead] gamemodes/redead/gamemode/cl_init.lua:421: bad argument #1 to 'pairs' (table expected, got nil)
1. pairs - [C]:-1
2. GoreRagdolls - gamemodes/redead/gamemode/cl_init.lua:421
3. unknown - gamemodes/redead/gamemode/cl_init.lua:151