All, you must provide more detail when reporting your issues.
"It doesn't work" is not a way that will help you get help in any way, shape, form, or fashion.
Megiddo had a nice link that I now can't find for how to report an error.
Provide Server console errors both from startup and when <x> is attempted. (most important)
Provide Game console errors both from startup and when <x> is attempted. . (not as, but yes, important)
If it just started happening, what did you just do? (new gamemode, addon, swep, sent, whatever, or update to any one of those)
Can you repeatedly cause the problem to happen? How could we, give steps.
Specifically to URestrict, what gamemode are you using? Many gamemodes use thier own restriction setting code which may overwrite what URestrict tries to do. DarkRP is a prime example. If you run Sandbox, default Gmod gamemode, and URestrict works fine, you need to speak to your gamemode's author to have the feature URestrict has that you want in the gamemode.