Synopsis
This is an error in the way the REXX script is written. Some WHEN or OTHERWISE keyword appears where it should not be.
Cause
You forgot to put a SELECT keyword before the WHEN keyword.
Cure
WHEN can't be used without a preceding SELECT. Make sure that there is one SELECT keyword before any WHEN.
Cause
You forgot to put a SELECT keyword before the OTHERWISE keyword.
Cure
OTHERWISE can't be used without a preceding SELECT. Make sure that there is one SELECT keyword before any OTHERWISE, (and no other OTHERWISE inbetween).
Cause
You tried to name a variable when or otherwise in a place where a WHEN or OTHERWISE keyword would be illegal.
Cure
In certain instructions, you cannot use (unquoted) REXX keywords WHEN or OTHERWISE for variable names.