I honestly don't know. I have 0% experience with DarkRP.
Try removing that entire block of code
if CLIENT then
if LocalPlayer():IsUserGroup("donator") or LocalPlayer():IsAdmin() then
TEAM_MTHEIF = AddExtraTeam("Master Thief", Color(150, 153, 0, 150), "models/player/arctic.mdl" , [[You are a faster and stronger thief. use your lockpick and keypad cracker to
get into peoples homes]], {"lockpick", "keypad_cracker"}, "mastertheif", 2, 150, 0, false, false)
TEAM_PARKOUR = AddExtraTeam("Parkour", Color(150, 140, 0, 130), "models/player/arctic.mdl" ,[[You are able to sneak up on you enimies and raid while they
dont expect it]], {"lockpick", "climb_swep"}, "parkour", 2, 135, 0, false, false)
end
end
and see if you still get any errors.