First attempt at fixing errors in confirmation screen.

app/scripts/lib/idStore.js

@@ -248,7 +248,7 @@ IdentityStore.prototype.addUnconfirmedTransaction = function (txParams, onTxDone
   function analyzeForDelegateCall(cb){
     if (txParams.to) {
       query.getCode(txParams.to, (err, result) => {
-        if (err) return cb(err)
+        if (err) return cb(err.message || err)
         var containsDelegateCall = self.checkForDelegateCall(result)
         txData.containsDelegateCall = containsDelegateCall
         cb()
@@ -264,7 +264,7 @@ IdentityStore.prototype.addUnconfirmedTransaction = function (txParams, onTxDone
     var gasLimit = '0x3b9aca00'
     estimationParams.gas = gasLimit
     query.estimateGas(estimationParams, function(err, result){
-      if (err) return cb(err)
+      if (err) return cb(err.message || err)
       if (result === estimationParams.gas) {
         txData.simulationFails = true
         query.getBlockByNumber('latest', true, function(err, block){
@@ -282,7 +282,7 @@ IdentityStore.prototype.addUnconfirmedTransaction = function (txParams, onTxDone
   }
 
   function didComplete (err) {
-    if (err) return cb(err)
+    if (err) return cb(err.message || err)
     configManager.addTx(txData)
     // signal update
     self._didUpdate()

app/scripts/metamask-controller.js

@@ -212,7 +212,6 @@ module.exports = class MetamaskController {
 
   newUnsignedTransaction (txParams, onTxDoneCb) {
     const idStore = this.idStore
-
     let err = this.enforceTxValidations(txParams)
     if (err) return onTxDoneCb(err)
     idStore.addUnconfirmedTransaction(txParams, onTxDoneCb, (err, txData) => {