Maybe we should add this one to a v4 troubleshooting FAQ as I've seen several variations of this error so far:
The reason for this error is you installed the patch incorrectly. You have to unzip the new OOTP4.EXE file into whatever directory you installed the game into and over-write the old OOTP4.EXE file. Unless you chose a different install folder when you installed the game you should unzip the patch to "C:\Program Files\OOTP4\" and say yes when prompted to over-write the old file. Let us know if this fixed it for you but I have a sneaking suspicion it will
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Markus, perhaps we need a patch installer
!
[ March 07, 2002: Message edited by: Killebrew ]</p>