Skyrim Workshop Mods Not Loading
After subscribing to Workshop items in Steam, the items appear in-game under Steam Workshop, but not under Mods. Therefore, I have no access to the on/off switch for the items and I am fairly certain that they have not been downloaded. Steam Workshop Mods not showing up in my game. » Thu May 24, 2012 6:37 am I subscribed to several mods, Sounds of Skyrim, a mod to show quest markers for the Stones of Barenziah, another one to light up the streets at night.
After subscribing to Workshop items in Steam, the items appear in-game under Steam Workshop, but not under Mods. Therefore, I have no access to the on/off switch for the items and I am fairly certain that they have not been downloaded.
I have taken the following steps and nothing has changed:
restart Cities: Skylines
restart Steam
restart my computer
verify integrity of game cache
unsubscribe / resubscribe to Workshop items
uninstall / reinstall Cities: Skylines
uninstall / reinstall Steam
It is worth noting that after uninstallation and reinstallation of both Cities: Skylines and Steam, my save data (custom maps, assets, and saved games) remains. I cannot locate this data on my machine as it is not in the Steam Cities: Skylines folder or the Colossal Order folder in My Documents.
Sadly, this other thread has been lost in obscurity and I am not alone with this issue. Hopefully someone out there can help those of us who for some reason can't play with mods!
EDIT:

I filed a Steam Support ticket, but I haven't had luck in the past with those. Additionally, I have noticed that this behavior persists in other games that used to work correctly (such as Civ 5).
The following is a potential workaround for anyone with this issue:
grab a friend who does not own C:S
have your friend log in to Steam on your computer
launch C:S on your friend's account
select the option to authorize shared library on this machine
subscribe to mods on your friend's account
boot up C:S on your friend's account and make sure the mods install
switch back to your account and subscribe to the same mods
boot up C:S on your own account and the mods will be usable because they are already downloaded on your machine

Skyrim Workshop Mods Not Loading
This works for me, but is a little cumbersome as you need the friend's login info anytime you want to get a new mod.