diff --git a/client/protocols/openvpnprotocol.cpp b/client/protocols/openvpnprotocol.cpp
index 38f8aba5..c310bd8b 100644
--- a/client/protocols/openvpnprotocol.cpp
+++ b/client/protocols/openvpnprotocol.cpp
@@ -226,6 +226,7 @@ void OpenVpnProtocol::onReadyReadDataFromManagementServer()
             else {
                 emit protocolError(ErrorCode::OpenVpnUnknownError);
             }
+            return;
         }
 
         QByteArray data(line.toStdString().c_str());
diff --git a/client/ui/mainwindow.cpp b/client/ui/mainwindow.cpp
index 5a968bdf..214151e5 100644
--- a/client/ui/mainwindow.cpp
+++ b/client/ui/mainwindow.cpp
@@ -37,6 +37,7 @@ MainWindow::MainWindow(QWidget *parent) :
     m_settings(new Settings)
 {
     ui->setupUi(this);
+    ui->label_error_text->clear();
     ui->widget_tittlebar->installEventFilter(this);
 
     ui->stackedWidget_main->setSpeed(200);
@@ -376,8 +377,7 @@ void MainWindow::onConnectionStateChanged(VpnProtocol::ConnectionState state)
 
 void MainWindow::onVpnProtocolError(ErrorCode errorCode)
 {
-    // TODO fix crash on Windows when starting vpn and another vpn already connected
-    //QMessageBox::critical(this, APPLICATION_NAME, errorString(errorCode));
+    ui->label_error_text->setText(errorString(errorCode));
 }
 
 void MainWindow::onPushButtonConnectClicked(bool checked)
@@ -529,6 +529,7 @@ void MainWindow::onTrayActivated(QSystemTrayIcon::ActivationReason reason)
 
 void MainWindow::onConnect()
 {
+    ui->label_error_text->clear();
     ui->pushButton_connect->setChecked(true);
     qApp->processEvents();
 
diff --git a/client/ui/mainwindow.ui b/client/ui/mainwindow.ui
index 6c20db41..ccba720b 100644
--- a/client/ui/mainwindow.ui
+++ b/client/ui/mainwindow.ui
@@ -267,7 +267,7 @@ QStackedWidget QWidget {
 </string>
      </property>
      <property name="currentIndex">
-      <number>1</number>
+      <number>0</number>
      </property>
      <widget class="QWidget" name="page_start">
       <widget class="QLabel" name="label_23">
@@ -1140,6 +1140,28 @@ color: #181922;
         <bool>false</bool>
        </property>
       </widget>
+      <widget class="QLabel" name="label_error_text">
+       <property name="geometry">
+        <rect>
+         <x>0</x>
+         <y>300</y>
+         <width>381</width>
+         <height>51</height>
+        </rect>
+       </property>
+       <property name="text">
+        <string>Error text</string>
+       </property>
+       <property name="scaledContents">
+        <bool>false</bool>
+       </property>
+       <property name="alignment">
+        <set>Qt::AlignCenter</set>
+       </property>
+       <property name="wordWrap">
+        <bool>true</bool>
+       </property>
+      </widget>
      </widget>
      <widget class="QWidget" name="page_sites">
       <property name="styleSheet">
diff --git a/deploy/windows.bat b/deploy/windows.bat
index 1a1bd1d9..f46d23c6 100644
--- a/deploy/windows.bat
+++ b/deploy/windows.bat
@@ -45,6 +45,7 @@ del "%OUT_APP_DIR:"=%\*.cpp"
 del "%OUT_APP_DIR:"=%\*.h"
 del "%OUT_APP_DIR:"=%\*.res"
 del "%OUT_APP_DIR:"=%\*.o"
+del "%OUT_APP_DIR:"=%\*.moc"
 del "%OUT_APP_DIR:"=%\*.lib"
 del "%OUT_APP_DIR:"=%\*.exp"
 echo "Deploying..."