How old are the add-ons your trying to use??
We've been recommending folks switch to using our Github code since about 4-5 months after we 'released' on our download site due to Gmod updates breaking.
Since, we've just not had time to make a new release. One is coming reasonably soon, or so I keep hearing whispers among Stickly Man and Megiddo.
I'm kind of shocked that 3-4 ULX addons would break at once after updating ULX unless they were extremely old to begin with.
We keep most functions compatible from 3.5 on.