Linux CUDA Miner StratumProxy fails: Unexpected token H in JSON at position 0

[vinnielima]

When running the ErgoStratumProxy binary for Linux:

./ErgoStratumProxy_Linux -s -p -u -l 3000

The following error occurs:

Ergo Stratum Proxy
Running at http://localhost:3000

[CONNECTION] Connected to server.
Unexpected token H in JSON at position 0
Unexpected token S in JSON at position 0
Unexpected token D in JSON at position 0
Unexpected token C in JSON at position 0
Unexpected token C in JSON at position 0
Unexpected token C in JSON at position 0
Unexpected token U in JSON at position 0
[CONNECTION] Disconnected from server.

The config.json has:

{
"node": "http://:"
}