What is causing "Network not available" error in rippled RPC call and how to fix it?
This error indicates that your server is not synchronized to the Ripple network and thus doesn't have current information. It's perfectly normal when your server first starts up -- it can take ten or fifteen minutes to sync up, depending on your bandwidth and hardware.

You should make sure you're actually connected to a few servers and have your validators correctly configured. The server_info RPC command can help.

The following config entries should help:

[ips]
23.23.201.55 51235
184.73.226.101 51235
54.225.112.220 51235
54.225.123.13 51235

[validators]
n9KPnVLn7ewVzHvn218DcEYsnWLzKerTDwhpofhk4Ym1RUq4TeGw
n9LFzWuhKNvXStHAuemfRKFVECLApowncMAM5chSCL9R5ECHGN4V
n94rSdgTyBNGvYg8pZXGuNt59Y5bGAZGxbxyvjDaqD9ceRAgD85P
n9LeQeDcLDMZKjx1TZtrXoLBLo5q1bR1sUQrWG7tEADFU6R27UBp
n9KF6RpvktjNs2MDBkmxpJbup4BKrKeMKDXPhaXkq7cKTwLmWkFr

[validation_quorum]
3


You can resolve r.ripple.com for a list of server IP addresses recommended by Ripple Labs. Currently the list is 54.225.123.13, 54.227.239.106, 107.21.251.218, 184.73.226.101, 23.23.201.55, and 54.225.112.220.