invalid argument error

gistfile1.txt

request = <SubRequest 'raiden_network' for <Function 'test_channel_to_api_dict[2-geth]'>>
token_addresses = ['q\xea\xc5d%\xe23z\xb1\r\xddQU\x1c\xf6\x8b\x1b\x84\xa0\xb5'], channels_per_node = 1, deposit = 200, settle_timeout = 16
blockchain_services = BlockchainServices(deploy_service=<raiden.network.rpc.client.BlockChainService...0f50>, <raiden.network.rpc.client.BlockChainService object at 0x7fc1d2ac0390>])
raiden_udp_ports = [29872, 29873], transport_class = <class 'raiden.network.transport.UDPTransport'>, send_ping_time = 0, max_unresponsive_time = 0
cached_genesis = None, reveal_timeout = 4

    @pytest.fixture
    def raiden_network(
            request,
            token_addresses,
            channels_per_node,
            deposit,
            settle_timeout,
            blockchain_services,
            raiden_udp_ports,
            transport_class,
            send_ping_time,
            max_unresponsive_time,
            cached_genesis,
            reveal_timeout):
    
        verbosity = request.config.option.verbose
    
        raiden_apps = create_apps(
            blockchain_services.blockchain_services,
            raiden_udp_ports,
            transport_class,
            verbosity,
            send_ping_time,
            max_unresponsive_time,
            reveal_timeout,
            settle_timeout
        )
    
        if not cached_genesis:
            create_network_channels(
                raiden_apps,
                token_addresses,
                channels_per_node,
                deposit,
                settle_timeout
            )
    
        for app in raiden_apps:
>           app.raiden.register_registry(app.raiden.chain.default_registry.address)

raiden/tests/fixtures/raiden_network.py:120: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
raiden/raiden_service.py:446: in register_registry
    self.pyethapp_blockchain_events.add_proxies_listeners(proxies)
raiden/blockchain/events.py:312: in add_proxies_listeners
    self.add_registry_listener(pyethapp_proxies.registry)
raiden/blockchain/events.py:282: in add_registry_listener
    tokenadded = registry_proxy.tokenadded_filter()
raiden/network/rpc/client.py:660: in tokenadded_filter
    to_block=to_block,
raiden/network/rpc/client.py:193: in new_filter
    return jsonrpc_client.call('eth_newFilter', json_data)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

self = <JSONRPCClient @29871>, method = 'eth_newFilter'
args = ({'address': '0x29d73fd964f1d5a9b2ba668c4ac31c61744a1b21', 'fromBlock': '', 'toBlock': '', 'topics': ['0xdffbd9ded1c09446f09377de547142dcce7dc541c8b0b028142b1eba7026b9e7']},)
request = <tinyrpc.protocols.jsonrpc.JSONRPCRequest object at 0x7fc1d2ab68d0>
reply = '{"jsonrpc":"2.0","id":256,"error":{"code":-32602,"message":"invalid argument 0: empty hex string"}}\n'
jsonrpc_reply = <tinyrpc.protocols.jsonrpc.JSONRPCErrorResponse object at 0x7fc1d2a87ed0>

    def call(self, method, *args):
        """ Do the request and returns the result.
    
            Args:
                method (str): The RPC method.
                args: The encoded arguments expected by the method.
                    - Object arguments must be supplied as an dictionary.
                    - Quantity arguments must be hex encoded starting with '0x' and
                    without left zeros.
                    - Data arguments must be hex encoded starting with '0x'
            """
        request = self.protocol.create_request(method, args)
        reply = self.transport.send_message(request.serialize())
        if self.print_communication:
            print json.dumps(json.loads(request.serialize()), indent=2)
            print reply
    
        jsonrpc_reply = self.protocol.parse_reply(reply)
        if isinstance(jsonrpc_reply, JSONRPCSuccessResponse):
            return jsonrpc_reply.result
        elif isinstance(jsonrpc_reply, JSONRPCErrorResponse):
>           raise JSONRPCClientReplyError(jsonrpc_reply.error)
E           JSONRPCClientReplyError: invalid argument 0: empty hex string

.tox/py27/src/pyethapp/pyethapp/rpc_client.py:413: JSONRPCClientReplyError
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Interrupted: stopping after 1 failures !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
=============================================================== 1 error in 49.11 seconds ===============================================================
ERROR: InvocationError: '/home/jacob/Dropbox/prgrms/ethereum/raiden/.tox/py27/bin/pytest --cov-append --exitfirst -s raiden/tests/api/test_api.py'
_______________________________________________________________________ summary ________________________________________________________________________
ERROR:   py27: commands failed