1783-NATR IP Address Translation Tab

I have this module connected to my laptop at my desk.
laptop ip: 192.168.10.127
laptop connected to port1 at the 1783-NATR

1783-NATR Public IP: 10.50.10.30
1783-NATR Gateway ip: 10.50.10.1
1783-NATR private IP: 192.168.10.193

when I try to create a new rule, with the ip addresses above, private and public, I get an error " invalid public ip", why?

Thanks

What is your subnet mask for the public side?

255.255.255.0

sorry, i found my mistake when i setup the rule.
i was using the assigned ip addresses for the private and public ports of the 1783NATR. i should have used different addresses other than those.

Thanks