diff --git a/lib/server.js b/lib/server.js
index 973e4eb..c7b511f 100644
--- a/lib/server.js
+++ b/lib/server.js
@@ -474,7 +474,7 @@ WalletService.prototype.getWalletFromIdentifier = function(opts, cb) {
           nextCoinNetwork(!!walletId);
         });
       });
-    }, function(walletId) {
+    }, function() {
       if (!walletId) return cb();
       return self.storage.fetchWallet(walletId, cb);
     });
@@ -932,6 +932,7 @@ WalletService.prototype._canCreateAddress = function(ignoreMaxGap, cb) {
     })) return cb(null, true);
 
     var bc = self._getBlockchainExplorer(latestAddresses[0].coin, latestAddresses[0].network);
+    if (!bc) return cb(new Error('Could not get blockchain explorer instance'));
     var activityFound = false;
     var i = latestAddresses.length;
     async.whilst(function() {
@@ -1079,6 +1080,7 @@ WalletService.prototype._getUtxos = function(coin, addresses, cb) {
   var networkName = Bitcore.Address(addresses[0]).toObject().network;
 
   var bc = self._getBlockchainExplorer(coin, networkName);
+  if (!bc) return cb(new Error('Could not get blockchain explorer instance'));
   bc.getUtxos(addresses, function(err, utxos) {
     if (err) return cb(err);
 
@@ -1508,6 +1510,7 @@ WalletService.prototype._sampleFeeLevels = function(coin, network, points, cb) {
   var self = this;
 
   var bc = self._getBlockchainExplorer(coin, network);
+  if (!bc) return cb(new Error('Could not get blockchain explorer instance'));
   bc.estimateFee(points, function(err, result) {
     if (err) {
       log.error('Error estimating fee', err);
@@ -2405,6 +2408,7 @@ WalletService.prototype.removePendingTx = function(opts, cb) {
 
 WalletService.prototype._broadcastRawTx = function(coin, network, raw, cb) {
   var bc = this._getBlockchainExplorer(coin, network);
+  if (!bc) return cb(new Error('Could not get blockchain explorer instance'));
   bc.broadcast(raw, function(err, txid) {
     if (err) return cb(err);
     return cb(null, txid);
@@ -2438,6 +2442,7 @@ WalletService.prototype.broadcastRawTx = function(opts, cb) {
 WalletService.prototype._checkTxInBlockchain = function(txp, cb) {
   if (!txp.txid) return cb();
   var bc = this._getBlockchainExplorer(txp.coin, txp.network);
+  if (!bc) return cb(new Error('Could not get blockchain explorer instance'));
   bc.getTransaction(txp.txid, function(err, tx) {
     if (err) return cb(err);
     return cb(null, !!tx);
@@ -2800,6 +2805,7 @@ WalletService.prototype._getBlockchainHeight = function(coin, network, cb) {
 
   function fetchFromBlockchain(cb) {
     var bc = self._getBlockchainExplorer(coin, network);
+    if (!bc) return cb(new Error('Could not get blockchain explorer instance'));
     bc.getBlockchainHeight(function(err, height) {
       if (!err && height > 0) {
         cache.current = height;
@@ -2991,6 +2997,7 @@ WalletService.prototype.getTxHistory = function(opts, cb) {
 
         var addressStrs = _.pluck(addresses, 'address');
         var bc = self._getBlockchainExplorer(wallet.coin, wallet.network);
+        if (!bc) return next(new Error('Could not get blockchain explorer instance'));
         bc.getTransactions(addressStrs, from, to, function(err, rawTxs, total) {
           if (err) return next(err);
 
@@ -3142,6 +3149,7 @@ WalletService.prototype.scan = function(opts, cb) {
 
   function checkActivity(wallet, address, cb) {
     var bc = self._getBlockchainExplorer(wallet.coin, wallet.network);
+    if (!bc) return cb(new Error('Could not get blockchain explorer instance'));
     bc.getAddressActivity(address, cb);
   };