Problem with csh

[Stephen P. Molnar]

I am running a new installation of Bullseye with the bash shell.
I have one application that I compile which requires the csh shell. WHen 
I change from bash to csh I get:

comp@AbNormal:~$ csh
Bad : modifier in $ '/'.
AbNormal:~%

I've never seen this before but the compilation process still worked.

What's going on?

Thanks in advance

-- Stephen P. Molnar, Ph.D. Molecular Modeling 614.312.7528 (c) Skype: 
smolnar1