All error codes

invalid_cidr

HTTP 422 Subnet is invalid

What happened

The subnet you sent is not a usable network address. It must be IPv4 in CIDR notation with a prefix between /8 and /30, and it must be the network address itself, with no host bits set.

What to do

Send the network address of the range, for example 10.0.0.0/24 rather than 10.0.0.5/24. If you hold a host address, clear the host bits before sending it.

Retrying

Fix the request and send it again.

How it arrives

{
    "type": "https://docs.fiberax.com/errors/invalid_cidr",
    "title": "Subnet is invalid",
    "status": 422,
    "code": "invalid_cidr",
    "request_id": "a277dcd1ca652c65"
}

Branch your code on code, never on the wording of title.