Installed the game, fixed some mods and in my steam workshop I am subscribed to some stuff. Even if I unsubscribe and then subscribe again.
When I start ACEO and go into the modding. I only see Native mods. As in airlines I downloaded and then made some changes too.
None of the workshop subscribed is there. I do not know what I am missing? I do see them in the workshop content folder of the game.
Where are you opening the game from? I remember there being some weird stuff with that at some point…
Playing on Steam, also have to write some extra stuff. The answer is still Steam 
I guess the is Steam then. Check if you are online and not in some offline mode.
Can confirm I am online.
I reinstalled the computer some time ago.
Installed the game recently and fixes some mods and so on today. The game starts fine but I only see native mods.
When going into the workshop I can see the airlines I’m subscribed to, so I tried to unsubscribe and subscribe to force an update of the files. It did update. But I still cannot see them in the modding tab when starting ACEO.
Means you start it out of the Steam library and not by a created desktop icon?
That is correct! ( I start the game in the steam library, the green button that says play! )
Weird. And I expect a reboot also didn’t helped?
Reinstall ACEO? (The forum is very intent on notifying me about every message here 
)
Will try that after a reinstall, because I am going to sleep. So I’ll start the computer tomorrow and write an update about the issue.
@humoresque But it’s newly installed, I mean I will probably try that now. Just to have tried it. 
So reinstalled the game! Reinstalled the UMF and mods, all loaded perfectly. But I still only see Native mods. Nothing from the Steam workshop is there.
I am going to try and force the system to download them again by deleting the content folder see what happens.
It did not work. It did download everything again. But it does not show up in the modding section of ACEO.
I only have one thing left that was suggested. Restarting the computer. With that said. I am going to sleep. If anyone have any ideas I’ll try them tomorrow.
I guess I’ll bite my self Just booted up after sleeping! Problem is Solved. If it was just the “restart” of the computer or that together with something else I have no idea.
I do still think that the Steam client or game went into an offline mode and lost the connection to the Workshop. 
Could be I guess. I could even load my old airport after all the mods where sorted. Just hope that pesky flight planner CTD bug get solved. Zekew has done such an awesome mod. Sad that a CTD bug found it’s way in the mod.