Only thing I can think of that would have changed and possibly messed with anyone in 5003 is the config files.
Look in your UDKGame/Config folder and see if there are multiple UDK[Whatever].ini files beneath all of the Default[whatever].ini files.
There should be one UDK file for every Default.
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On that same note, the Default resolution changed in 5003, so if it's worth a try, you can look for either UDKSystemSetting.ini (this is the one the game uses), or DefaultSystemSettings(this is just the default one it uses if you haven't ever ran the game). In either of those search for "ResX" and ResY, and set them to your preferred resolution.
E.G I run 1920x1080, so it'd be
ResX=1920
ResY=1080
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On that same token, you can look into editing both SystemSettings.ini, and RenegadeX.ini to reset all of your graphics settings and see if that's where the error comes from.