If you got Phx, Wire, Stargate, or any other big addon off of garrysmod.org then it's outdated and possibly corrupt. SVN is the newest version.
First, you will need the program tortoisesvn
(click here)Now install that. Yes do it
Now go to your addons folder and make a new empty folder called whatever you want
now right click it and choose "SVN checkout"
leave all the options the same except where it asks you to put an URL. Choose what addon you want from here and put it in:
Code:
Advanced MOTD: http://page81.no-ip.org/svn/meeces2911/trunk/Advanced%20MOTD/
Map Icons: http://gmod-mapicons.googlecode.com/svn/trunk
Spawn Icons: http://gmod-spawnicons.googlecode.com/svn/trunk
Achievements: http://gmodachievements.googlecode.com/svn/trunk
Pyroteknix: http://pyroteknix.googlecode.com/svn/trunk
Cannons: http://gmodcannons.googlecode.com/svn/trunk
Player Mod: https://opensvn.csie.org/TRT_BETA/PMod
Simpson Skin: http://gmoddederma.googlecode.com/svn/trunk/Simpson%20style
NPC Control: http://svn2.assembla.com/svn/cKlTXW0D8r3ikmabIlDkbG/trunk/npcgun
Halo SWEPS: http://halo-sweps-garrysmod.googlecode.com/svn/trunk
DroolHUD: http://droolhud.googlecode.com/svn/trunk
PC Mod: http://pcmod.googlecode.com/svn/trunk
PC Mod 2: http://pcmod.googlecode.com/svn/pcmod2/
Easy Engine: svn://svn.gmod.de/enginemod
Wire Mod: https://svn.wiremod.com/svn/wiremod/wire
Wire Model Pack: https://svn.wiremod.com/svn/wiremod/wire%20model%20pack%201
Wire Extras: http://svn.dagamers.net/wiremodextras/trunk
Wire Rings: http://page81.no-ip.org/svn/meeces2911/trunk/Wire%20Rings/
Advanced Duplicator: https://svn.wiremod.com/svn/wiremod/Adv%20Duplicator
Wire Mod 2: https://svn.wiremod.com/svn/wire2
VMF Suite: http://vmfsuite.googlecode.com/svn/trunk
VMF Mega Pack: https://opensvn.csie.org/VMFMegaPack/VMF
PHX Model Pack 3: https://phoenix-storms.svn.sourceforge.net/svnroot/phoenix-storms
Spacebuild Model Pack: http://spacebuildmodelpack.googlecode.com/svn/trunk/SpacebuildModelPackAlpha2
Startrek Shuttle Pack: http://stshuttlepack.googlecode.com/svn/trunk/STShuttlePack
Total Train Model Pack: https://opensvn.csie.org/trainpack
Life Support 2: http://tools.assembla.com/svn/LifeSupport2 (This contains a zip, open it and install like any other addon)
Life Support 2 - Petrol Mod: http://tools.assembla.com/svn/b9DO4Awyer3lRoabIlDkbG
Life Support 2 - Resource Transit Systems: http://opensvn.csie.org/lsResorceTransitSystems
Resource Distribution 2: https://svn.wiremod.com/svn/RDistrib2/trunk/RD2
CubeSystems - Life Cube: http://cube-systems.googlecode.com/svn/trunk/Life%20Cube
Custom Addon Framework: http://customaddonframework.googlecode.com/svn/trunk/Custom%20Addon%20Framework
Life Support 3 - Core: http://customaddons.googlecode.com/svn/trunk/Life%20Support%203
Life Support 3 - Entities: http://customaddons.googlecode.com/svn/trunk/Life%20Support%20Entities
Life Support 3 - PC Mod: http://customaddons.googlecode.com/svn/trunk/Life%20Support%20PC%20Mod
Life Support 3 - Mining Addon: http://customaddons.googlecode.com/svn/trunk/Mining%20Addon
Life Support 3 - Petrol Systems: http://customaddons.googlecode.com/svn/trunk/Petrol%20Systems
Life Support 3 - Gas Systems: http://svn.assembla.com/svn/gassystems2
Life Support 3 - Resource Transit System: http://customaddons.googlecode.com/svn/trunk/Resource%20Transit%20System
Life Support 3 - Custom Damage System: http://customaddons.googlecode.com/svn/trunk/Custom%20Damage%20System
Resource Distribution 3: http://customaddons.googlecode.com/svn/trunk/Resource%20Distribution
CubeSystems - Life Cube 2: http://cube-systems.googlecode.com/svn/trunk/Life%20Cube%202
SG-Mod: http://sg-mod.svn.sourceforge.net/svnroot/sg-mod (Copy contents to main garrysmod folder)
Stargate - Main: https://svn.wiremod.com/svn/stargate/trunk/addons/stargate
Stargate - Resources: https://svn.wiremod.com/svn/stargate/trunk/addons/stargate_resources
Stargate - Extras/Overloader: http://sgose.googlecode.com/svn/trunk
Stargate - Replicator: http://replicatorai.googlecode.com/svn/trunk/Replicator%20AI
Stargate - GDO 1.3: http://stargate-gdo.googlecode.com/svn/trunk
Stargate - GDO 1.4: http://page81.no-ip.org/svn/meeces2911/trunk/Stargate%20GDO/
Stargate - McKay Pack: http://stargatemckaypack.googlecode.com/svn/trunk
Catdaemon - Shieldgen: http://www.meteornet.net/catsvn/shieldgen
Catdaemon - Rings: http://www.meteornet.net/catsvn/rings
Catdaemon - Cloakgen: http://www.meteornet.net/catsvn/cloakgen
Catdaemon - Harvester: http://www.meteornet.net/catsvn/harvester
Catdaemon - Shuttle: http://www.meteornet.net/catsvn/shuttle
Catdaemon - Shuttle Extras: http://www.meteornet.net/catsvn/shuttle_extras
Catdaemon - Weapon Stripper: http://www.meteornet.net/catsvn/weapon_stripper
Catdaemon - Wraith Dart: http://www.meteornet.net/catsvn/wraithdart
Catdaemon - SG Pack: https://svn.wiremod.com/svn/stargate/trunk/addons/catdaemon_stargate
CubeSystems - Supergate: http://cube-systems.googlecode.com/svn/trunk/supergate%20addon
CubeSystems - Energy Gates: http://cube-systems.googlecode.com/svn/trunk/stargate%20addon%20with%20energy
CubeSystems - Life Cube 3: http://cube-systems.googlecode.com/svn/trunk/Alienate_Life%20Cube%203
CubeSystems - Admin GUI: http://cube-systems.googlecode.com/svn/trunk/Cubesystems_AdminGui
GMDM Resources: https://svn.wiremod.com/svn/stargate/trunk/addons/gmdm_resources
GCombat Core: http://gcombatcore.googlecode.com/svn/trunk/ (I think this one is old, get the non-svn 08 version instead)
GCombat Extended: http://gcombat-extended.googlecode.com/svn/trunk/GCX (Do what the "MOVE MY CONTENTS TO YOUR MAIN GARRYSMOD FOLDER" tells you to do)
Doctor Who: http://doctorwho.googlecode.com/svn/trunk/doctorwho
ULX: http://ulyssesmod.net/ulx/trunk
ULib: http://ulyssesmod.net/ulib/trunk
New Admin: http://newadmin.googlecode.com/svn/trunk/release1.1/
Evolve: http://evolvemod.googlecode.com/svn/trunk/dev/
Sickness Models: http://subversion.assembla.com/svn/SicknessModel/
EvoCity2: http://subversion.assembla.com/svn/Evocity2/ (type: "+r_hunkalloclightmaps 0" without the quotation marks on the console)
RagMod: https://ragmod.svn.sourceforge.net/svnroot/ragmod/latest (type: "bind t rm_ragdolize" and "bind y rm_reset" on console to use it properly)
ShoTGuNGuY's Player Models: http://sggplayermodels.svn.sourceforge.net/svnroot/sggplayermodels/
Half-Life 2 Beta Player Models: http://hl2betaplayermodels.googlecode.com/svn/trunk/
Halo Player Models: http://haloplayermodels.googlecode.com/svn/trunk/
Simple Prop Protection: http://simplepropprotection.googlecode.com/svn/trunk/
TF2 Unlockables Spawnlist: http://tf2unlocks.googlecode.com/svn/trunk/settings/ (Checkout to Settings folder)
Now type that in and hit OK. If it asks you for a username and password it will either be:
anonsvn
anonsvn
or
anon
anon
Now let it do it's thing. Whenever a new version comes out you can just right click the folder and hit "svn update".