PDR1238S
<FIELD> fieldname specifies a page-based action but is not a variable field. Page action fields must have a name starting with %% to indicate that they are variables.
What happened: You specified P as the second character of a <FIELD> tag's action parameter but you did not define the field as a variable (that is, the variable's name does not begin with %%). Only field variables may have a "page" action value. The <FIELD> tag fieldname value is given.
What to do: Make sure you have correctly defined all fields.