CHARMM Development Project Forums CHARMM Interfaces MMTSB Running genPSF.pl

Hi all,
I've been unable to solve this error so far. When I execute the command to generate a PSF as follows:

"genPSF.pl dskr2v5_min.pdb -par param=27 -xplor -cmd file"

I get the following error:

*** CHARMM terminated abnormally
*** Last command: open unit 10 read form name "C:/CHARMM_Nichols/CHARMM/test/data/top_all27_prot_na.rtf"
*** CHARMM output follows:

CHARMM> open unit 10 read form name "C:/CHARMM_Nichols/CHARMM/test/data/top_all27_prot_na.rtf"

***** LEVEL 0 WARNING FROM *****
***** The environment variable contained only a colon.
******************************************
BOMLEV ( 0) IS REACHED - TERMINATING. WRNLEV IS 5


It doesn't describe which environment variable contains only a colon. I've checked CHARMMDATA and CHARMMEXEC and they appear fine.