COBCH1898 Incompatible conditional compilation expressions

An expression within one of the ISO2002 conditional compilation directives contains incorrect logic.
There are a number of reason that could cause this error, such as a compilation variable being defined as a numeric and then evaluated as an alphanumeric (or vice versa), or a variable within the expression being previously subjected to the OFF phrase. Check and correct your logic within the conditional compilation directive or the definition of the variable.