Can't add a static route in tec cg4131com

I am having a problem on a tec cg4131com. Every time I enter information on the static route screen, I get the error "Failed. Please try again later, Gateway IP must be reachable. Netmask must match route address". it doesn't matter what is entered, the same message is displayed.

The destination ip range is 192.168.1.0 to 192.156.1.254 with subnet of 255.255.255.0

The Gateway private Internal IP is 10.1.10.1 with the external public IP of 76.146.228.161

I'm connecting to an Enterasys C3 with three vlan's.  vlan 25 is the 10.1.10.0 network, vlan 26 is the 192.168.1.0 and vlan 27 is the 192.168.2.0 network. Only vlan 25 and 26 are currently being used. The C3 has been tested without being connected to the CG4131com, with no problem moving between vlans. Once connected to the CG4131com it no longer recognizes the 192.168.1.0 network. I know a static route will solve the resolution, but I just get the same error every time I try to add. I have read the directions in the manual, but the instructions are limited and vague. Below is what has been entered.

Name FCC VLan 26

Destination Subnet 192.168.1.0

Subnet Mask 255.255.255.0

Gateway IP 10.1.10.1

Also There are 4 reserved ip's in the cg4131com

10.1.10.2 C3 address 1

10.1.10.3

10.1.10.4 Laptop

10.3.10.5 VPN

10.1.10.6 C3 address 2

There are 5 port forwards also in the cg4131com

VPN to 10.1.10.5

RDP, Tightvnc-out, Tight vnc-in, DVR to 10.1.10.2