From what I read nobody stated exactly what type of errors they were receiving.. Im running on a bastardized system with an old install.. Have reinstalled windows overtop of the then present installation, and had other probs.(which was quite awhile back) But UT rocks on my system! I love it and have played and own all fps games since doom...
Now I do get one error every once in awhile stating "Assertion Failed: actor class[file e:/unreal220engine" ect.... heres a work around:
Epic receives reports about UT CD Problems:
We are seeing reports of several different problems that appear to be due to problems reading files of the game CD.
For example:
Critical: appError called:
Critical: Assertion failed: InPos>=0
There are also other examples, such as problems with running a particular map. Some people have reported problems applying the 402 patch because some file (such as botpack.u or umenu.u) is not recognized properly from their CD.
..........
You might try the following reinstall procedure, simple as it
seems it has helped a lot of people with weird errors.
Corrupted files are sometimes installed without any error messages with some
CD-ROM drives; data is copied to your HD with read-errors, but for some
reason the CD drive doesn't warn the installer and everything appears to
have installed OK.
Copy everything from the CD to the hard drive, (running scandisk first to be
absolutely sure there's nothing wrong with the hard drive) then install from
the hard drive to the final destination folder. (you'll still need the CD in
the drive for playing.) Also, please make sure you install into a clean
(new) folder, not on top of any existing UT or UT-demo content.
If your only problem is with patching, you only need to copy the system directory from the CD. When the patch installer asks you for your CD directory, give it the directory in which the temporary system directory resides (if you copied the system directory to c:\UTtemp\system, then tell the patch installer that c:\UTtemp is your CD.
http://unreal.epicgames.com/
this was ripped from:
http://www.cached.net/Essentials/Essentials-U.htm
Now get it fixed and go kick some *** !