All the other RPC methods are working for me, except the validate_address one, which always returns an error. I tried both curl (CLI) and PHP, neither of them work, they return the same error:
{"result":null,"error":{"code":-32700,"message":"Parse error"},"id":null}
If anyone can help, it would be much appreciated.
I'm going to assume you're copying the example from the docs, which has an error in that params should read "params" (quoted).
A corrected and working example looks like:
$ curl localhost:18084/json_rpc -d \
'{"jsonrpc":"2.0","id":"0","method":"validate_address", "params":{"address":"42go2d3XqA9Mx4HjZoqr93BHspcMxwAUBivs3yJKV1FyTycEcbgjNyEaGNEcgnUE9DDDAXNanzB16YgMt88Sa8cFSm2QcHK","any_net_type":true,"allow_openalias":true}'
{
"id": "0",
"jsonrpc": "2.0",
"result": {
"integrated": false,
"nettype": "mainnet",
"openalias_address": "",
"subaddress": false,
"valid": true
}
}