RENUMBER is a machine language program loaded as an Applesoft program, when run, relocates the machine language up
to HIMEM in your system. DOS defaults to MAXFILES 3, so HIMEM is on page boundary $9600, in a 48K Apple. Changing MAXFILES moves HIMEM off this page boundary.
RENUMBER's relocator still does the move, but it doesn't relocate the address properly. The usual result is that the system drops into the monitor in the address range of $0200 - $0300.