Illegal modification of .ENDM directive keyword by lexical
 operation.

    Error: While your macro definition contains a .ENDM directive
    that ends the macro definition, the .ENDM directive is modified
    by a lexical operator so that it can no longer be recognized as a
    .ENDM directive keyword after lexical processing.

    User Action: Change the statement to avoid modifying the .ENDM
    directive keyword with lexical operator processing. See Chapter
    3 in the Reference Manual for information about using lexical
    operators.