I was experiencing the exact same problem as the 0P. CLIPROMPTUPDATE =1 did the trick for me.
Thank you very much!
I have service pack 1 installed... Is there a service pack 1.1 for C3d 2013?
BTW, why on God's green earth does Autodesk invariably choose to change the default settings of obscure system variables?
P.S. technically the result of my Lisp expression did not appear on the command line but it did finally appear in the command history which it had been absent from until I set CLIPROMPTUPDATE=1
Changing the "clipromptupdate" setting to "1" now allows me to see the LISP repsonses on the screen. YEAH!!
This is very important when debugging custom routines. WARNING: "clipromtupdate" needs to be reset whenever you change the current profile (options command)!
This works in 2013 & 2014.