diff --git a/AM2RLauncher/AM2RLauncher/Language/Text.Designer.cs b/AM2RLauncher/AM2RLauncher/Language/Text.Designer.cs
index d5efb6a..c4b1e8a 100644
--- a/AM2RLauncher/AM2RLauncher/Language/Text.Designer.cs
+++ b/AM2RLauncher/AM2RLauncher/Language/Text.Designer.cs
@@ -19,7 +19,7 @@ namespace AM2RLauncher.Language {
     // -Klasse über ein Tool wie ResGen oder Visual Studio automatisch generiert.
     // Um einen Member hinzuzufügen oder zu entfernen, bearbeiten Sie die .ResX-Datei und führen dann ResGen
     // mit der /str-Option erneut aus, oder Sie erstellen Ihr VS-Projekt neu.
-    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("System.Resources.Tools.StronglyTypedResourceBuilder", "16.0.0.0")]
+    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("System.Resources.Tools.StronglyTypedResourceBuilder", "17.0.0.0")]
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
     [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]
     public class Text {
@@ -366,6 +366,15 @@ namespace AM2RLauncher.Language {
             }
         }
         
+        /// <summary>
+        ///   Sucht eine lokalisierte Zeichenfolge, die $NAME is an invalid git URL! ähnelt.
+        /// </summary>
+        public static string InvalidGitURL {
+            get {
+                return ResourceManager.GetString("InvalidGitURL", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Sucht eine lokalisierte Zeichenfolge, die Java not found! Cannot generate an APK without a Java installation. Please make sure that Java is installed and added to PATH. ähnelt.
         /// </summary>
diff --git a/AM2RLauncher/AM2RLauncher/Language/Text.resx b/AM2RLauncher/AM2RLauncher/Language/Text.resx
index cf80e4d..1ba47a2 100644
--- a/AM2RLauncher/AM2RLauncher/Language/Text.resx
+++ b/AM2RLauncher/AM2RLauncher/Language/Text.resx
@@ -219,6 +219,9 @@
   <data name="InternetConnectionDrop" xml:space="preserve">
     <value>Couldn't establish an internet connection! Try again later!</value>
   </data>
+  <data name="InvalidGitURL" xml:space="preserve">
+    <value>$NAME is an invalid git URL!</value>
+  </data>
   <data name="JavaNotFound" xml:space="preserve">
     <value>Java not found! Cannot generate an APK without a Java installation. Please make sure that Java is installed and added to PATH.</value>
   </data>
diff --git a/AM2RLauncher/AM2RLauncher/MainForm/MainForm.Events.cs b/AM2RLauncher/AM2RLauncher/MainForm/MainForm.Events.cs
index 61ac52a..13292f3 100644
--- a/AM2RLauncher/AM2RLauncher/MainForm/MainForm.Events.cs
+++ b/AM2RLauncher/AM2RLauncher/MainForm/MainForm.Events.cs
@@ -846,8 +846,18 @@ namespace AM2RLauncher
         /// </summary>
         private void CustomMirrorTextBoxLostFocus(object sender, EventArgs e)
         {
+            // Check first, if the text is a valid git repo
+            Regex gitURLRegex = new Regex("https://.*\\.git");
+            string mirrorText = customMirrorTextBox.Text;
+            if (!gitURLRegex.IsMatch(mirrorText))
+            {
+                log.Info("User used " + mirrorText + " as a custom Mirror, didn't pass git validation test.");
+                //TODO: Localize these
+                MessageBox.Show(Language.Text.InvalidGitURL.Replace("$NAME", mirrorText), Language.Text.ErrorWindowTitle, MessageBoxType.Error);
+                return;
+            }
 
-            currentMirror = customMirrorTextBox.Text;
+            currentMirror = mirrorText;
             CrossPlatformOperations.WriteToConfig("CustomMirrorText", currentMirror);
 
             log.Info("Overwriting mirror in gitconfig.");
@@ -856,7 +866,6 @@ namespace AM2RLauncher
             string gitConfigPath = CrossPlatformOperations.CURRENTPATH + "/PatchData/.git/config";
             if (!File.Exists(gitConfigPath)) return;
             string gitConfig = File.ReadAllText(gitConfigPath);
-            Regex gitURLRegex = new Regex("https://.*\\.git");
             Match match = gitURLRegex.Match(gitConfig);
             gitConfig = gitConfig.Replace(match.Value, currentMirror);
             File.WriteAllText(gitConfigPath, gitConfig);
diff --git a/AM2RLauncher/AM2RLauncher/MainForm/MainForm.UI.cs b/AM2RLauncher/AM2RLauncher/MainForm/MainForm.UI.cs
index dc9de28..a5500de 100644
--- a/AM2RLauncher/AM2RLauncher/MainForm/MainForm.UI.cs
+++ b/AM2RLauncher/AM2RLauncher/MainForm/MainForm.UI.cs
@@ -140,7 +140,6 @@ namespace AM2RLauncher
             log.Info("Set Launcher CWD to " + Environment.CurrentDirectory);
 
             // But log actual folder location nonetheless
-            // TODO: test if this logs correctly on windows now
             log.Info("Actual Launcher location: " + Path.GetDirectoryName(AppDomain.CurrentDomain.BaseDirectory));
 
             // Set the language to what User wanted or choose local language
@@ -150,7 +149,6 @@ namespace AM2RLauncher
 
             log.Info("Language has been set to: " + Thread.CurrentThread.CurrentUICulture.EnglishName);
 
-
             #region VARIABLE INITIALIZATION
             log.Info("Beginning UI initialization...");