diff --git a/Habitica/build.gradle b/Habitica/build.gradle
index 6d8fe2ec9..41478587e 100644
--- a/Habitica/build.gradle
+++ b/Habitica/build.gradle
@@ -50,10 +50,10 @@ dependencies {
         transitive = true
     }
 
-    compile 'com.android.support:appcompat-v7:23.0.1'
-    compile 'com.android.support:design:23.0.1'
-    compile 'com.android.support:gridlayout-v7:23.0.1'
-    compile 'com.android.support:recyclerview-v7:23.0.1'
+    compile 'com.android.support:appcompat-v7:23.1.1'
+    compile 'com.android.support:design:23.1.1'
+    compile 'com.android.support:gridlayout-v7:23.1.1'
+    compile 'com.android.support:recyclerview-v7:23.1.1'
 
     // Image Loading/Caching
     compile 'com.squareup.picasso:picasso:2.5.2'
diff --git a/Habitica/res/values/strings.xml b/Habitica/res/values/strings.xml
index 234ab176f..64874f8ca 100644
--- a/Habitica/res/values/strings.xml
+++ b/Habitica/res/values/strings.xml
@@ -120,6 +120,13 @@
     <string name="internal_error_api">There seems to be a problem with the server. Try again later.</string>
     <string name="network_up">Your internet connection just got back!</string>
 
+    <string name="authentication_error_title">Authentication Error</string>
+    <string name="authentication_error_body">Your Username and/or Password was incorrect.</string>
+
+    <string name="login_validation_error_title">Validation Error</string>
+    <string name="login_validation_error_fieldsmissing">You have to fill out all fields.</string>
+    <string name="login_validation_error_invalid_email">Invalid email address.</string>
+
     <string name="checklist.title.add">Add checklist</string>
     <string name="checklist.title.edit">Edit checklist</string>
     <string name="checklist.item.hint">Add item…</string>
diff --git a/Habitica/src/com/habitrpg/android/habitica/APIHelper.java b/Habitica/src/com/habitrpg/android/habitica/APIHelper.java
index 786740046..550350073 100644
--- a/Habitica/src/com/habitrpg/android/habitica/APIHelper.java
+++ b/Habitica/src/com/habitrpg/android/habitica/APIHelper.java
@@ -184,23 +184,31 @@ public class APIHelper implements ErrorHandler, Profiler {
 		if (cause.getKind().equals(RetrofitError.Kind.NETWORK)) {
             //It also handles timeouts
             showConnectionProblemDialog(activity, R.string.network_error_no_network_body);
-		}else{
-            /*
-             * CONVERSION An exception was thrown while (de)serializing a body.
-             * HTTP A non-200 HTTP status code was received from the server e.g. 502, 503, etc...
-             * UNEXPECTED An internal error occurred while attempting to execute a request.
-             */
-            showConnectionProblemDialog(activity,R.string.internal_error_api);
-        }
+            return cause;
+        } else if (cause.getKind().equals(RetrofitError.Kind.HTTP)) {
+            int status = cause.getResponse().getStatus();
+            if (status == 401) {
+                showConnectionProblemDialog(activity, R.string.authentication_error_title, R.string.authentication_error_body);
+                return cause;
+            } else if (status >= 500 && status < 600) {
+                showConnectionProblemDialog(activity,R.string.internal_error_api);
+                return cause;
+            }
+		}
+        showConnectionProblemDialog(activity, R.string.internal_error_api);
 
-		return cause;
+        return cause;
 	}
 
-    private void showConnectionProblemDialog(final Activity activity, final int resourceMessageString){
+    private void showConnectionProblemDialog(final Activity activity, final int resourceMessageString) {
+        showConnectionProblemDialog(activity, R.string.network_error_title, resourceMessageString);
+    }
+
+    private void showConnectionProblemDialog(final Activity activity, final int resourceTitleString, final int resourceMessageString){
         activity.runOnUiThread(new Runnable() {
             public void run() {
                 new AlertDialog.Builder(activity)
-                        .setTitle(R.string.network_error_title)
+                        .setTitle(resourceTitleString)
                         .setMessage(resourceMessageString)
                         .setNeutralButton(android.R.string.ok, new DialogInterface.OnClickListener() {
                             public void onClick(DialogInterface dialog, int which) {
diff --git a/Habitica/src/com/habitrpg/android/habitica/LoginActivity.java b/Habitica/src/com/habitrpg/android/habitica/LoginActivity.java
index f711d5b29..5d1466f79 100644
--- a/Habitica/src/com/habitrpg/android/habitica/LoginActivity.java
+++ b/Habitica/src/com/habitrpg/android/habitica/LoginActivity.java
@@ -159,11 +159,19 @@ public class LoginActivity extends AppCompatActivity
                 email = String.valueOf(mEmail.getText());
                 password = String.valueOf(mPasswordET.getText());
                 cpassword = String.valueOf(mConfirmPassword.getText());
+				if (username.length() == 0 || password.length() == 0 || email.length() == 0 || cpassword.length() == 0) {
+					showValidationError(R.string.login_validation_error_fieldsmissing);
+					return;
+				}
                 mApiHelper.registerUser(v,username,email,password,cpassword);
             } else {
                 String username,password;
                 username = String.valueOf(mUsernameET.getText());
                 password = String.valueOf(mPasswordET.getText());
+				if (username.length() == 0 || password.length() == 0) {
+					showValidationError(R.string.login_validation_error_fieldsmissing);
+					return;
+				}
                 mApiHelper.connectUser(username,password, LoginActivity.this);
             }
 		}
@@ -316,4 +324,17 @@ public class LoginActivity extends AppCompatActivity
         mProgressBar.setVisibility(View.GONE);
         showSnackbar(getString(R.string.unknown_error));
     }
+
+	private void showValidationError(int resourceMessageString) {
+		mProgressBar.setVisibility(View.GONE);
+		new android.support.v7.app.AlertDialog.Builder(this)
+					.setTitle(R.string.login_validation_error_title)
+					.setMessage(resourceMessageString)
+					.setNeutralButton(android.R.string.ok, new DialogInterface.OnClickListener() {
+						public void onClick(DialogInterface dialog, int which) {
+						}
+					})
+					.setIcon(R.drawable.ic_warning_black)
+					.show();
+	}
 }