Hello i cant get on coop when i get on coop it loads 1 dot and my friend says he got disconnected and after all the dots load it says your partner has disconnect in the console it says : Opened Steam Socket NS_SERVER ( socket 342 )
Opened Steam Socket NS_CLIENT ( socket 344 )
Network: IP unknown, mode MP, dedicated No, ports 27015 SV / 27005 CL
Parent cvar in client.dll not allowed (movement_anim_playback_minrate)
Game supporting (2) split screen players
maxplayers set to 1
Error: Material "debug/debugluxels" uses unknown shader "DebugLuxels"
Error: Material "fillrate_0" uses unknown shader "FillRate"
Error: Material "debugnormalmap_1" uses unknown shader "DebugNormalMap"
Error: Material "debugdrawenvmapmask_2" uses unknown shader "DebugDrawEnvmapMask"
Error: Material "debugdepth_3" uses unknown shader "DebugDepth"
Error: Material "debugdepth_4" uses unknown shader "DebugDepth"
Requesting texture value from var "$basetexture" which is not a texture value (material: dev/constant_color)
KV Conditional: Unknown symbol INPUTSWAPAB
KV Conditional: Unknown symbol INPUTSWAPAB
Steam config directory: /Users/sarahsmith/Library/Application Support/Steam/SteamApps/common/Portal 2/platform/config
--- Missing Vgui material vgui/hud/commands/gesture_sitspin_orange
--- Missing Vgui material vgui/hud/commands/gesture_Spinjump
--- Missing Vgui material vgui/hud/commands/gesture_headspin
--- Missing Vgui material vgui/hud/commands/gesture_pretzelwave
--- Missing Vgui material vgui/hud/commands/gesture_sitspin_orange
--- Missing Vgui material vgui/hud/commands/gesture_Spinjump
--- Missing Vgui material vgui/hud/commands/gesture_headspin
--- Missing Vgui material vgui/hud/commands/gesture_pretzelwave
Hud element 'CHUDPaintAmmo' doesn't have an entry 'PaintAmmo' in scripts/HudLayout.res
Hud element 'CHUDVSScorePanel' doesn't have an entry 'VSScorePanel' in scripts/HudLayout.res
Hud element 'CHudSubtitles' doesn't have an entry 'HudSubtitles' in scripts/HudLayout.res
Hud element 'CHudSaveStatus' doesn't have an entry 'HudSaveStatus' in scripts/HudLayout.res
--- Missing Vgui material vgui/hud/commands/change_this
--- Missing Vgui material vgui/hud/commands/gesture_sitspin_orange
--- Missing Vgui material vgui/hud/commands/gesture_Spinjump
--- Missing Vgui material vgui/hud/commands/gesture_headspin
--- Missing Vgui material vgui/hud/commands/gesture_pretzelwave
--- Missing Vgui material vgui/hud/commands/gesture_sitspin_orange
--- Missing Vgui material vgui/hud/commands/gesture_Spinjump
--- Missing Vgui material vgui/hud/commands/gesture_headspin
--- Missing Vgui material vgui/hud/commands/gesture_pretzelwave
Hud element 'CHUDPaintAmmo' doesn't have an entry 'PaintAmmo' in scripts/HudLayout.res
Hud element 'CHUDVSScorePanel' doesn't have an entry 'VSScorePanel' in scripts/HudLayout.res
Hud element 'CHudSubtitles' doesn't have an entry 'HudSubtitles' in scripts/HudLayout.res
Hud element 'CHudSaveStatus' doesn't have an entry 'HudSaveStatus' in scripts/HudLayout.res
--- Missing Vgui material vgui/hud/commands/gesture_smallwave
Error: Material "fillrate_0" uses unknown shader "FillRate"
Error: Material "debugnormalmap_1" uses unknown shader "DebugNormalMap"
Error: Material "debugdrawenvmapmask_2" uses unknown shader "DebugDrawEnvmapMask"
Error: Material "debugdepth_3" uses unknown shader "DebugDepth"
Error: Material "debugdepth_4" uses unknown shader "DebugDepth"
Error: Material "debug/debugluxels" uses unknown shader "DebugLuxels"
Requesting texture value from var "$basetexture" which is not a texture value (material: dev/constant_color)
Unknown command "cl_thirdperson"
Unknown command "cl_thirdperson"
DLCMANAGER: RequestDlcUpdate has no new content.
DLCMANAGER: RequestDlcUpdate has no new content.
CGameUIConVarRef mp_gamemode doesn't point to an existing ConVar
ConVarRef cl_colorblind doesn't point to an existing ConVar
maxplayers set to 2
---- Host_NewGame ----
Host_NewGame on map mp_coop_lobby_3
exec: couldn't exec skill1.cfg
Executing listen server config file
exec: couldn't exec listenserver.cfg
exec: couldn't exec skill1.cfg
==== calling mapspawn.nut
Unable to load sprite material materials/sprites/gunsmoke.vmt!
Unable to load sprite material materials/sprites/bubble.vmt!
PrecacheScriptSound 'music.mp_coop_lobby_3_lbout' failed, no such sound script entry
PrecacheScriptSound 'glados.Gesture1_03' failed, no such sound script entry
PrecacheScriptSound 'glados.Gesture1_04' failed, no such sound script entry
PrecacheScriptSound 'glados.Gesture1_05' failed, no such sound script entry
PrecacheScriptSound 'announcer.mp_coop_wall_5security01' failed, no such sound script entry
PrecacheScriptSound 'announcer.mp_announcer_hub01' failed, no such sound script entry
PrecacheScriptSound 'announcer.mp_announcer_hub02' failed, no such sound script entry
PrecacheScriptSound 'announcer.mp_announcer_hub03' failed, no such sound script entry
PrecacheScriptSound 'glados.COOP_SCORE_COMMENT01' failed, no such sound script entry
PrecacheScriptSound 'glados.Radar01' failed, no such sound script entry
PrecacheScriptSound 'glados.Radar02' failed, no such sound script entry
PrecacheScriptSound 'glados.Radar03' failed, no such sound script entry
PrecacheScriptSound 'glados.Gesture1_06' failed, no such sound script entry
PrecacheScriptSound 'glados.Gesture1_01' failed, no such sound script entry
PrecacheScriptSound 'glados.Gesture1_02' failed, no such sound script entry
PrecacheScriptSound 'glados.Gesture1_07' failed, no such sound script entry
Dynamic prop prop_dynamic: no sequence named:idle
Commentary: Could not find commentary data file 'maps/mp_coop_lobby_3_commentary.txt'.
51.410: Sending UDP connect to public IP 127.0.0.1:27015
Server using '<none>' lobbies, requiring pw no, lobby id 0
RememberIPAddressForLobby: lobby 0 from address loopback
-> Reservation cookie 18600004c9c50eb: reason netsupport
Connection to Steam servers successful.
VAC secure mode is activated.

Portal 2 Coop
Map: mp_coop_lobby_3
Players: 1 (0 bots) / 2 humans
Build: 4941
Server Number: 1

No pure server whitelist. sv_pure = 0
SignalXWriteOpportunity(3)
SignalXWriteOpportunity(3)
Can't find factory for entity: wearable_item
NULL Ent in UTIL_PrecacheOther
Requesting texture value from var "$basetexture" which is not a texture value (material: dev/bloomadd)
Requesting texture value from var "$basetexture" which is not a texture value (material: dev/no_pixel_write)
Requesting texture value from var "$basetexture" which is not a texture value (material: dev/lumcompare)
Requesting texture value from var "$basetexture" which is not a texture value (material: dev/blurgaussian_3x3)
Requesting texture value from var "$basetexture" which is not a texture value (material: dev/fade_blur)
Requesting texture value from var "$basetexture" which is not a texture value (material: dev/halo_add_to_screen)
[PORTAL2 PUZZLEMAKER] --------START loading assets--------

[PORTAL2 PUZZLEMAKER] ---------END loading assets---------

==== calling mapspawn.nut
Weapon_portalgun has no owner when trying to upgrade!
Receiving uncompressed update from server
Shadow memory (m_ShadowDecals) growing [8192]
Shadow memory (m_ShadowSurfaces) growing [8192]
-> Reservation cookie 0: reason netsupport
Dropped Hds0303 from server (Server shutting down)

if anyone can figure out whats wrong post why it wont work

Try:

It seems that you're missing a bunch of files, verifying the game cache should fix this.
Maybe also tell your friend to do this so you both have it working.