Urgent problem. Java exception message "There are no possible fo r step n"

All,

I'm really not an OS developer but am supporting a third-party package that
is based on OS.

From what I'm able to determine it looks as though a step expects to contain
one action and that it can't find one.  However, I can't see anything wrong
with the action definition, and browsers and TurboXML do not detect any
problems.

Can anyone suggest what I might look for in the xml file that defines the
steps and actions?

Jim van Scoyoc