JSON Error in Ubuntu 16.04

Hello

I try to use ethminer in Ubuntu 16.04 and I get this error. Looked it up but did not find anything helpful.

comp@comp:~$ ethminer -G -F http://eu1.ethermine.org:4444/"address"
[OPENCL]:Found suitable OpenCL device [Ellesmere] with 8040267776 bytes of GPU memory
miner 10:34:43.804|ethminer Getting work package...
✘ 10:34:43.947|ethminer Failed to submit hashrate.
✘ 10:34:43.947|ethminer Dynamic exception type: jsonrpc::JsonRpcException
std::exception::what: Exception -32603 : INTERNAL_ERROR: : {"id":999,"jsonrpc": "2.0","result": false,"error": "Invalid JSON request"}
JSON-RPC problem. Probably couldn't connect. Retrying in 1...

Any ideas? Thanks