More information would be of great help in helping us determine what is causing.
Are you getting any errors in console (server AND client) after ULX is added?
Make sure your using latest ULib and ULX from our github -
https://github.com/Nayruden/Ulysses/archive/master.zip (you only need, for now, the ULib and ULX within the zip, not the others)
What gamemode? If it's darkRP, then, trust me, it's likely not just ULX, but a combination of things. DarkRP has never seemed to like ULX, especially when Fadmin is enabled, or you've created a Owner group instead of a team called owner and don't have proper superadmin inheritance set up.
I've read some of the comments at the Steam workshop release of FA:S 2 - it doesn't seem to be stable - at all. It's an alpha release. That would tend to make me think that, though it might only happen when you add ULX, it's not something we'll be able to fix.
How many other addons?
Can you start without any other addons except for ULib and ULX, then add 1 or 2 addons at a time until you start seeing issues? (Example - Shut down server - ULib - ULX - start/test - shut down/add FA:S 2 - start/test - shut down/add
- start/test)