Creo Elements Direct Customizations

I am having difficulty with having Creo Elements Direct 18.1 reading my AM_CUSTOMIZE file.  I am getting the same response no matter what I try.

LISP error: The function AM..... (no matter what function I am trying to load) is undefined.

What am I missing?  Is it syntax in the file?  Do I need to define something ahead of time?

I am new to Creo and this file is a copy of the one that has been used for years.  It works in 15.50 but we are upgrading to 18.1 so I am guessing there has been changes, but I need help "upgrading" this file.

Please help

Thanks in Advance,

Mike