I have the same similar issue on 6500 too, on both
12.2-33.SXJ10
and
15.1-2.SYS8ip nat inside source static udp 192.168.z.z 4500 a.b.c.d 4500 extendable%Port 4500 is being used by system min4500and I have removed all nat statements to try too and no ...