Hi Kevin,
I have just tried to setup a new static route to 10.19.163.0/24 which would be included if i extend the 10.19.162.0/24 to be a /23 but get the same error.
I have also tried to setup a route to 10.19.240.0/24 which isn't in use anywhere on our network and get the same error. I have also tried this one with a different gateway with the same result.
I have also just tried to update a static routes name (no other changes) and get the same error weirdly.
I have tried both the save button at the bottom and the floating one on the right, both have the same effect.
There is nothing showing in the event log or change log to help me narrow down what the issue is.
I have been through most of the "config" pages and can't see any reference to other configurations relating to that subnet.
I have also tried it in two different browsers just in case.
Any other ideas?