Some WorkShop Items Not Downloading

Some of the items i download from the workshop download, some dont, and even some that download, do not show up in my menus ingame at all. How can this be fixed?

Any console errors?

This is what i get upon starting gmod and loading gm_construct

Initializing Awesomium…
No Kinect SDK
Lua JIT is DISABLED!
Unknown command “cl_thirdperson”
Using joystick ‘Xbox360 controller’ configuration
JOY_AXIS_X: mapped to Side (absolute)
JOY_AXIS_Y: mapped to Forward (absolute)
JOY_AXIS_Z: unmapped
JOY_AXIS_R: mapped to Look (absolute)
JOY_AXIS_U: mapped to Turn (absolute)
JOY_AXIS_V: unmapped
Advanced Joystick settings initialized
Unknown command “hud_showemptyweaponslots”
Unknown command “sv_backspeed”
Not playing a local game.

 RUNLUA:UpdateMapList()


```html
 RUNLUA:UpdateLanguages()
PREP OK
Error, bad server command lua_error_url ''
Lua JIT is DISABLED!
Serverside loaded
Made by Nocturne
TEST [maps/9_11_twintowers_v8.bsp][maps/gm_construct.bsp]
TEST [maps/c5m2_park.bsp][maps/gm_construct.bsp]
TEST [maps/gm_bigcity.bsp][maps/gm_construct.bsp]
TEST [maps/gm_grand_build.bsp][maps/gm_construct.bsp]
TEST [maps/gm_ski_jumping_v1.bsp][maps/gm_construct.bsp]
TEST [maps/gm_tsukuba_circuit.bsp][maps/gm_construct.bsp]
Using map cycle file 'cfg/mapcycle_default.txt'.  ('cfg/mapcycle.txt' was not found.)
Nav File is wrong or something (4)
Garry's Mod
http://loading.garrysmod.com/
sandbox
gm_construct
1
76561198052852094
Attemped to precache unknown particle system "generic_smoke"!
Requesting 1 lua files from the server
Warning: WorldTwoTextureBlend found on a non-displacement surface (material: gm_construct/flatgrass). This wastes perf for no benefit.
clientside lua startup!
Lua JIT is DISABLED!
Clientside loaded
Requesting texture value from var "$dummyvar" which is not a texture value (material: NULL material)
Compact freed 557056 bytes
Using joystick 'Xbox360 controller' configuration
JOY_AXIS_X:  mapped to Side (absolute)
JOY_AXIS_Y:  mapped to Forward (absolute)
JOY_AXIS_Z:  unmapped
JOY_AXIS_R:  mapped to Look (absolute)
JOY_AXIS_U:  mapped to Turn (absolute)
JOY_AXIS_V:  unmapped
Advanced Joystick settings initialized
Redownloading all lightmaps

[editline]2nd December 2013[/editline]

Maybe i need to clean my gmod folder? i've never done it, some directions would be nice but im not sure this would even help

[editline]2nd December 2013[/editline]

Its now to the point where ANYTHING i download comes out on the console like this,

Not loading addon 'addons/big_speaker_149646056.gma' - file doesn't exist
Couldn't mount addon [big speaker][addons/big_speaker_149646056.gma]
Removing bad addon addons/big_speaker_149646056.gma
Not loading addon 'addons/bugatti_veyron_198998343.gma' - file doesn't exist
Couldn't mount addon [Bugatti Veyron][addons/bugatti_veyron_198998343.gma]
Removing bad addon addons/bugatti_veyron_198998343.gma
Not loading addon 'addons/flying_car_197546840.gma' - addon header invalid
Couldn't mount addon [Flying Car][addons/flying_car_197546840.gma]
Removing bad addon addons/flying_car_197546840.gma

Try deleting your garrysmod/downloads (now download) and all the .gma files in garrysmod/addons.

I reinstalled Garrys mod all together. it didnt delete the addons, but it fixed the errors. my problem seemed to be that some mods require having other mods to work, thanks for the help