"Record your encryption passphrase" ... "Unable to find a shell"

[Adam Funk]

Hi,

I helped a friend set up an Ubuntu laptop with the Ubuntu-standard
encrypted home directories option.  He showed me the "Record your
encryption passphrase" dialog yesterday, but when he clicked on the
option to go ahead, a terminal opened up with just an "Unable to find
a shell" error message.

How is the system unable to find a shell?  (It has bash & the other
system defaults on it.)  How to fix this?

Thanks,
Adam