1. Read the error message - you have some kind of problem with your basic setup, in particlar with the topology/parameter files. It usually (read: always) is important to pay close attention to the first error message. When you want (free) help from others, do not hide the error message in an attachment.
You have not yet reached the part of the problem you asked about in the first place.
2. You have a commercial version of CHARMM, and thus you have the privilege of commercial support via Accelrys - use it, your company has probably paied real money for it!
3. The stream commands to unknown files makes it difficult to judge the quality of your input.
4. Still there are several inconsistencies in your input. Do you actually intend to read a trajectory contained in the file named pept500.cor? And what does the variable @9 represent in this command?
"open unit 21 read unform name @9pept500.cor"
!Innocent, but what makes you think that "type HT" refers to water oxygens?
coor anal select type HT end - ! Water oxygens
!Recheck "type NT"
site select type NT end multi - ! and the amide hydrogens
!What file did you open for reading on unit 1, referenced below?
firstu 1 nunit 1 skip ...
!Did you use Periodic Boundary Conditions (of the simple type supported by this CHARMM command)? What about variables 6,7, and 8?
I hope the above helps you formulating good questions to Accelrys support!