So far, no proven error with the program has been shown by anyone.
However, it has been many Gmod and even ULib updates since any posted in this thread.
Some things to remember I've learned over the past few pages;
Can't test it in Single player.
Gmod doesn't run the limit check function in SP. (This uses modified functions of those, but, they don't run either)
UNoLimited version - v1 requires no ULib. If using ULib, doesn't matter what version
v2+ requires latest ULib SVN for group checking.
Configuration;
Limits - I've seen several try to set 'limits' for v2 to more than 2x. Can't do it. UNolimited falls back to normal limit if number is higher than 2.
Groups - If you're using custom groups (owner for example, for some reason, seems to be popular), you'd need to add it to your v2 configuration.
If not using v2, well, I forget how I coded it, but I'm pretty sure you need to actually be superadmin or admin in Gmod's 'isusergroup' function.
DarkRP - Doesn't work with this 95+% of the time. Last I saw, DarkRP uses the same Gmod functions for it's prop ban system that this does. As I've suggested before, if using DarkRP, ask the authors of it to extend it's prop banning system to include limit checking system for diff group levels. (It's really not hard to do)
URestrict - Latest versions of Urestrict include same/tweaked code from UNoLimited. They'll fight each other. (Though at this time, many reports of URestrict being broken exist, and we've not seen much, if any, of Jay lately. We hope he's ok)
Now, with all the above checked... try to give some more detail. Using which version of UNoLimited? v1 is the simplest.
If your not using a conflicting gamemode or mod (that use the same functions this does), v1 should work for you as long as Gmod sees you as an admin or superadmin.
If using v2, does your server console at start up show it loading when ULib is showing shared module startup?
No errors? I'd find that odd. Even an error at startup should occur if a problem is occurring. Conflicting mods would show one or the other mod hooks failing on the server then being removed, usually the first time a prop is spawned.