I have the same....

[2018-01-24 18:26:30] Starting Stratum on stratum+tcp://btcz.suprnova.cc:5586
[2018-01-24 18:26:30] 4 miner threads started, using 'scrypt' algorithm.
[2018-01-24 18:26:30] Binding thread 3 to cpu 3
[2018-01-24 18:26:30] Binding thread 0 to cpu 0
[2018-01-24 18:26:30] Binding thread 1 to cpu 1
[2018-01-24 18:26:30] Binding thread 2 to cpu 2
[2018-01-24 18:26:31] Failed to get extranonce2_size
[2018-01-24 18:26:31] JSON-RPC call failed: (unknown reason)
[2018-01-24 18:26:31] ...retry after 30 seconds

How did you solved it?

Thanks!