title: Can't start Hyperledger Explorer
body: <p>I have Hyperledger Fabric running on an Ubuntu instance. I created it using the Composer installation scripts. I can ping it and see it working in the Playground.</p>
  
  <p>Now, I'm trying to launch Hyperledger Explorer, but it fails silently. The log says, <code>Failed to find a peer matching the url</code>.</p>
  
  <p>Here's what I have in my <code>connection.json</code>, created by Composer:
  <code>
  {
      "name": "hlfv1",
      "x-type": "hlfv1",
      "x-commitTimeout": 300,
      "version": "1.0.0",
      "client": {
          "organization": "Org1",
          "connection": {
              "timeout": {
                  "peer": {
                      "endorser": "300",
                      "eventHub": "300",
                      "eventReg": "300"
                  },
                  "orderer": "300"
              }
          }
      },
      "channels": {
          "composerchannel": {
              "orderers": ["orderer.example.com"],
              "peers": {
                  "peer0.org1.example.com": {}
              }
          }
      },
      "organizations": {
          "Org1": {
              "mspid": "Org1MSP",
              "peers": ["peer0.org1.example.com"],
              "certificateAuthorities": ["ca.org1.example.com"]
          }
      },
      "orderers": {
          "orderer.example.com": {
              "url": "grpc://localhost:7050"
          }
      },
      "peers": {
          "peer0.org1.example.com": {
              "url": "grpc://localhost:7051",
              "eventUrl": "grpc://localhost:7053"
          }
      },
      "certificateAuthorities": {
          "ca.org1.example.com": {
              "url": "http://localhost:7054",
              "caName": "ca.org1.example.com"
          }
      }
  }
  </code></p>
  
  <p>Here's what I wrote in my config.json for the Explorer. As suggested, I replaced all grpcs with grpc:
  <code>
  {
      "network-config": {
          "Org1": {
              "name": "Org1",
              "mspid": "Org1MSP",
              "peer1": {
                  "requests": "grpc://localhost:7051",
                  "events": "grpc://localhost:7053",
                  "server-hostname": "peer0.org1.example.com"
              },
              "admin": {
                  "key": "/home/ubuntu/fabric-dev-servers/fabric-scripts/hlfv11/composer/crypto-config/peerOrganizations/org1.example.com/users/Admin@org1.example.com/msp/keystore",
                  "cert": "/home/ubuntu/fabric-dev-servers/fabric-scripts/hlfv11/composer/crypto-config/peerOrganizations/org1.example.com/users/Admin@org1.example.com/msp/signcerts"
              }
          }
      },
      "host": "localhost",
      "port": "8080",
      "channel": "composerchannel",
      "keyValueStore": "/tmp/fabric-client-kvs",
      "eventWaitTime": "30000",
      "users":[
          {
             "username":"admin",
             "secret":"adminpw"
          }
       ],
      "pg": {
          "host": "127.0.0.1",
          "port": "5432",
          "database": "fabricexplorer",
          "username": "hppoc",
          "passwd": "password"
      },
      "license": "Apache-2.0"
  }
  </code></p>
  
  <p>And here's the full error log:</p>
  
  <pre><code>postgres://hppoc:password@127.0.0.1:5432/fabricexplorer
  Please open web browser to access ：http://localhost:8080/
  [31m[2018-05-16 12:08:39.563] [ERROR] FabricClientProxy - [39mFailed to find a peer matching the url grpc://localhost:7051
  [31m[2018-05-16 12:08:39.564] [ERROR] FabricClientProxy - [39mFailed to find a peer matching the url grpc://localhost:7051
  /home/ubuntu/blockchain-explorer/app/FabricClientProxy.js:37
          if (this.channels[org][this.channelName] == undefined)
                                ^
  
  TypeError: Cannot read property 'composerchannel' of undefined
      at FabricClientProxy.getChannelForOrg (/home/ubuntu/blockchain-explorer/app/FabricClientProxy.js:37:25)
      at getChainInfo (/home/ubuntu/blockchain-explorer/app/query.js:91:34)
      at Object.getChannelHeight (/home/ubuntu/blockchain-explorer/app/query.js:190:9)
      at getMaxBlockNum (/home/ubuntu/blockchain-explorer/app/service/blockscanner.js:152:18)
      at Object.syncBlock (/home/ubuntu/blockchain-explorer/app/service/blockscanner.js:40:9)
      at Timeout._onTimeout (/home/ubuntu/blockchain-explorer/app/listener/blocklistener.js:46:22)
      at ontimeout (timers.js:482:11)
      at tryOnTimeout (timers.js:317:5)
      at Timer.listOnTimeout (timers.js:277:5)
  </code></pre>