I keep getting this -

[2018-03-08 12:28:20] Binding thread 1 to cpu 1
[2018-03-08 12:28:20] 4 miner threads started, using 'scrypt' algorithm.
[2018-03-08 12:28:20] Binding thread 0 to cpu 0
[2018-03-08 12:28:20] Binding thread 2 to cpu 2
[2018-03-08 12:28:20] Binding thread 3 to cpu 3
[2018-03-08 12:28:20] HTTP request failed: The requested URL returned error: 500 Internal Server Error
[2018-03-08 12:28:20] json_rpc_call failed, retry after 30 seconds
[2018-03-08 12:28:50] HTTP request failed: The requested URL returned error: 500 Internal Server Error
[2018-03-08 12:28:50] json_rpc_call failed, retry after 30 seconds
[2018-03-08 12:29:20] HTTP request failed: The requested URL returned error: 500 Internal Server Error
[2018-03-08 12:29:20] json_rpc_call failed, retry after 30 seconds
[2018-03-08 12:29:50] HTTP request failed: The requested URL returned error: 500 Internal Server Error
[2018-03-08 12:29:50] json_rpc_call failed, retry after 30 seconds
[2018-03-08 12:30:20] HTTP request failed: The requested URL returned error: 500 Internal Server Error
[2018-03-08 12:30:20] json_rpc_call failed, retry after 30 seconds

My .bat file -

minerd --url=http://127.0.0.1:33420 --userpass=rpc_nicecoin:a9e72a27aa3de054c49622750


Dont know what i am doing wrong