Fix NFE. Update Gradle version.

app/build.gradle

@@ -8,8 +8,8 @@ android {
         applicationId 'com.blogspot.e_kanivets.moneytracker'
         minSdkVersion 17
         targetSdkVersion 23
-        versionCode 15
-        versionName '1.7.8'
+        versionCode 16
+        versionName '1.7.9'
     }
     signingConfigs {
         releaseConfig {
@@ -64,4 +64,4 @@ dependencies {
     androidTestCompile 'com.crittercism.dexmaker:dexmaker:1.4'
     androidTestCompile 'com.crittercism.dexmaker:dexmaker-dx:1.4'
     androidTestCompile 'com.crittercism.dexmaker:dexmaker-mockito:1.4'
-}
+}

app/src/main/java/com/blogspot/e_kanivets/moneytracker/activity/account/AddAccountActivity.java

@@ -65,23 +65,31 @@ public boolean onCreateOptionsMenu(Menu menu) {
     public boolean onOptionsItemSelected(MenuItem item) {
         switch (item.getItemId()) {
             case R.id.action_done:
-                addAccount();
-
-                setResult(RESULT_OK);
-                finish();
+                if (addAccount()) {
+                    setResult(RESULT_OK);
+                    finish();
+                } else showToast(R.string.wrong_number_text);
                 return true;
 
             default:
                 return super.onOptionsItemSelected(item);
         }
     }
 
-    private void addAccount() {
+    private boolean addAccount() {
         String title = etTitle.getText().toString().trim();
-        double initSum = Double.parseDouble(etInitSum.getText().toString().trim());
+
+        double initSum;
+        try {
+            initSum = Double.parseDouble(etInitSum.getText().toString().trim());
+        } catch (NumberFormatException e) {
+            e.printStackTrace();
+            return false;
+        }
+
         String currency = (String) spinner.getSelectedItem();
 
         Account account = new Account(title, initSum, currency);
-        accountController.create(account);
+        return accountController.create(account) != null;
     }
-}
+}

build.gradle

@@ -3,7 +3,7 @@ buildscript {
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.1.2'
+        classpath 'com.android.tools.build:gradle:2.1.3'
         classpath 'com.neenbedankt.gradle.plugins:android-apt:1.4'
         classpath 'com.getkeepsafe.dexcount:dexcount-gradle-plugin:0.5.2'
     }

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
-#Tue Apr 19 13:31:21 GMT+02:00 2016
+#Wed Aug 24 14:58:14 GMT+02:00 2016
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-2.10-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-2.14.1-all.zip