This compiler error will occur if you try to use the name of a built-in function as variable name.

For example:

var 
    NumDaysInMonth // this is the name of a built-in function !
begin
 

This error often occurs when naming variables that start with "num"(presumably for "number"). In those cases it is important to remember to put the "n" prefix at the front.

Topic 109902, last updated on 13-Apr-2020