I'm getting the above error when I make queries or invokes from Postman to my ubuntu server.
Following are the running containers and the full error log:
    CONTAINER ID        IMAGE                        COMMAND                  CREATED             STATUS              PORTS                                            NAMES
    f07e92dcdf7e        my_node/node-app             "npm start"              33 minutes ago      Up 33 minutes       0.0.0.0:9999->4000/tcp                           my_node
    f8b84ebc7510        hyperledger/fabric-peer      "peer node start"        33 minutes ago      Up 33 minutes       0.0.0.0:7056->7051/tcp, 0.0.0.0:7058->7053/tcp   peer1.org1.example.com
    301407e3285b        hyperledger/fabric-peer      "peer node start"        33 minutes ago      Up 33 minutes       0.0.0.0:8051->7051/tcp, 0.0.0.0:8053->7053/tcp   peer0.org2.example.com
    09ef3c426af2        hyperledger/fabric-peer      "peer node start"        33 minutes ago      Up 33 minutes       0.0.0.0:8056->7051/tcp, 0.0.0.0:8058->7053/tcp   peer1.org2.example.com
    d46778455d1a        hyperledger/fabric-peer      "peer node start"        33 minutes ago      Up 33 minutes       0.0.0.0:7051->7051/tcp, 0.0.0.0:7053->7053/tcp   peer0.org1.example.com
    1e14126d1920        hyperledger/fabric-ca        "sh -c 'fabric-ca-..."   33 minutes ago      Up 33 minutes       0.0.0.0:7054->7054/tcp                           ca_peerOrg1
    5bd780de76a9        hyperledger/fabric-ca        "sh -c 'fabric-ca-..."   33 minutes ago      Up 33 minutes       0.0.0.0:8054->7054/tcp                           ca_peerOrg2
    beafd29107fa        hyperledger/fabric-orderer   "orderer"                33 minutes ago      Up 33 minutes       0.0.0.0:7050->7050/tcp                           orderer.example.com
Full error log:
[2017-09-29 03:11:22.270] [DEBUG] Helper - [crypto_ecdsa_aes]: ecdsa signature:  Signature {
  r: <BN: 8afc8e33226a0f3a364ceb4c4826d3c442f26d92dda33fd7ff12027e214e354f>,
  s: <BN: 1d7ff1d66ae71f27571b5d90e95f18fbcc1c52ee8954ae03c330f22c5206333b>,
  recoveryParam: 0 }
error: [Peer.js]: sendProposal - timed out after:45000
error: [Peer.js]: sendProposal - timed out after:45000
error: [client-utils.js]: sendPeersProposal - Promise is rejected: Error: REQUEST_TIMEOUT
    at Timeout._onTimeout (/usr/src/app/node_modules/fabric-client/lib/Peer.js:107:19)
    at ontimeout (timers.js:386:11)
    at tryOnTimeout (timers.js:250:5)
    at Timer.listOnTimeout (timers.js:214:5)
error: [client-utils.js]: sendPeersProposal - Promise is rejected: Error: REQUEST_TIMEOUT
    at Timeout._onTimeout (/usr/src/app/node_modules/fabric-client/lib/Peer.js:107:19)
    at ontimeout (timers.js:386:11)
    at tryOnTimeout (timers.js:250:5)
    at Timer.listOnTimeout (timers.js:214:5)
Here is my repo link: https://github.com/pagito/balance_transfer Kindly help.