diff --git a/.gitignore b/.gitignore
index 1ec5fe61c..cf79703f0 100644
--- a/.gitignore
+++ b/.gitignore
@@ -33,6 +33,7 @@ desktop.ini
 
 # experimental dev work
 /libs/3rdparty/mupdf/mupdf/
+/libs/3rdparty/SOLR/
 
 /docs-src/_meta/HTML standards and designs/
 /docs-src/_meta/layouts/
diff --git a/Qiqqa.Build/Packaging/Include/couninst.exe b/Qiqqa.Build/Packaging/Include/couninst.exe
index a1e17b863..02acc50ef 100644
Binary files a/Qiqqa.Build/Packaging/Include/couninst.exe and b/Qiqqa.Build/Packaging/Include/couninst.exe differ
diff --git a/Qiqqa/Common/Configuration/ConfigurationManager.cs b/Qiqqa/Common/Configuration/ConfigurationManager.cs
index b60f11291..e3677c1f6 100644
--- a/Qiqqa/Common/Configuration/ConfigurationManager.cs
+++ b/Qiqqa/Common/Configuration/ConfigurationManager.cs
@@ -64,7 +64,7 @@ public static bool IsInitialized
         private readonly Lazy<string> __startupDirectoryForQiqqa = new Lazy<string>(() => UnitTestDetector.StartupDirectoryForQiqqa);
         public string StartupDirectoryForQiqqa => __startupDirectoryForQiqqa.Value;
 
-        private readonly Lazy<string> __BaseDirectoryForQiqqa = new Lazy<string>(() =>
+        private Lazy<string> __BaseDirectoryForQiqqa = new Lazy<string>(() =>
         {
             // Command-line parameters override the Registry:
             string[] args = Environment.GetCommandLineArgs();
@@ -138,9 +138,30 @@ public static bool IsInitialized
             // If we get here, use the default path
             return Path.GetFullPath(Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData), @"Quantisle/Qiqqa"));
         });
+        private bool __BaseDirectoryForQiqqaIsFixedFromNowOn = false;
+        public bool BaseDirectoryForQiqqaIsFixedFromNowOn
+        {
+            get => __BaseDirectoryForQiqqaIsFixedFromNowOn;
+            set
+            {
+                __BaseDirectoryForQiqqaIsFixedFromNowOn = true; // doesn't matter what you set 'value' to: we only can turn this lock ON and then it's DONE.
+            }
+        }
         public string BaseDirectoryForQiqqa
         {
-            get => __BaseDirectoryForQiqqa.Value;
+            get 
+            {
+                return __BaseDirectoryForQiqqa.Value;
+            }
+            set
+            {
+                if (BaseDirectoryForQiqqaIsFixedFromNowOn)
+                {
+                    throw new AccessViolationException($"Internal Error: Rewriting Qiqqa Base Path to '{value}' after it was locked for writing is indicative of erroneous use of the setter, i.e. setter is useed too late in the game!");
+                }
+                __BaseDirectoryForQiqqa = new Lazy<string>(() => Path.GetFullPath(value));
+                RegistrySettings.Instance.Write(RegistrySettings.BaseDataDirectory, value);
+            }
         }
 
         public string BaseDirectoryForUser
diff --git a/Qiqqa/Common/MessageBoxControls/UnhandledExceptionMessageBox.xaml.cs b/Qiqqa/Common/MessageBoxControls/UnhandledExceptionMessageBox.xaml.cs
index a24df0996..b087f94c2 100644
--- a/Qiqqa/Common/MessageBoxControls/UnhandledExceptionMessageBox.xaml.cs
+++ b/Qiqqa/Common/MessageBoxControls/UnhandledExceptionMessageBox.xaml.cs
@@ -45,14 +45,6 @@ public static void DisplayException(Exception ex)
                 throw new OutOfMemoryException("Out of memory", ex);
             }
 
-            // the garbage collection is not crucial for the functioning of the dialog itself, hence dump it into a worker thread.
-            SafeThreadPool.QueueUserWorkItem(o =>
-            {
-                // Collect all generations of memory.
-                GC.WaitForPendingFinalizers();
-                GC.Collect(GC.MaxGeneration, GCCollectionMode.Forced, true, true);
-            });
-
             string useful_text_heading = "Something unexpected has happened, but it's okay. " + ex.Message;
             string useful_text_subheading = "You can continue working, but we would appreciate it if you would send us some feedback on what you were doing when this happened.";
 
diff --git a/Qiqqa/DocumentLibrary/WebLibraryStuff/WebLibraryDetailControl.xaml.cs b/Qiqqa/DocumentLibrary/WebLibraryStuff/WebLibraryDetailControl.xaml.cs
index bb0561d07..65e966bd4 100644
--- a/Qiqqa/DocumentLibrary/WebLibraryStuff/WebLibraryDetailControl.xaml.cs
+++ b/Qiqqa/DocumentLibrary/WebLibraryStuff/WebLibraryDetailControl.xaml.cs
@@ -784,7 +784,7 @@ private void UpdateLibraryStatistics_Headers()
                 {
                     TextLibraryCount.Text = String.Format("{0} document(s) in this library, {1}",
                         web_library_detail.Xlibrary?.PDFDocuments_IncludingDeleted_Count ?? 0,
-                        web_library_detail.LastSynced.HasValue ? $"last synced on {web_library_detail.LastSynced.Value.ToString()}" : @"has never been synced yet");
+                        web_library_detail.LastSynced.HasValue ? $"which was last synced on {web_library_detail.LastSynced.Value}" : @"which has never been synced yet");
                 }
 
                 // The wizard stuff
diff --git a/Qiqqa/Main/LoginStuff/LoginWindow.xaml b/Qiqqa/Main/LoginStuff/LoginWindow.xaml
index 87cee4940..9eaa37eea 100644
--- a/Qiqqa/Main/LoginStuff/LoginWindow.xaml
+++ b/Qiqqa/Main/LoginStuff/LoginWindow.xaml
@@ -1,56 +1,100 @@
 <commongui:StandardWindow
-  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
-  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-  xmlns:local_gui="clr-namespace:Utilities.GUI;assembly=Utilities"
-  xmlns:commongui="clr-namespace:Qiqqa.Common.GUI"
-  xmlns:configgui="clr-namespace:Qiqqa.Common.Configuration"
-  
-  xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
-  xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
-  mc:Ignorable="d" 
-  x:Class="Qiqqa.Main.LoginStuff.LoginWindow"
-  
-  SizeToContent="Height"
-  Width="400"
-  ShowInTaskbar="True"
-  ResizeMode="NoResize"
-  WindowStartupLocation="CenterScreen"
-  Icon="/Qiqqa;component/Qiqqa.ico"
->
-    <local_gui:AugmentedBorder Margin="10"  >
+    x:Class="Qiqqa.Main.LoginStuff.LoginWindow"
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:commongui="clr-namespace:Qiqqa.Common.GUI"
+    xmlns:configgui="clr-namespace:Qiqqa.Common.Configuration"
+    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+    xmlns:local_gui="clr-namespace:Utilities.GUI;assembly=Utilities"
+    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+    Width="400"
+    Icon="/Qiqqa;component/Qiqqa.ico"
+    ResizeMode="NoResize"
+    ShowInTaskbar="True"
+    SizeToContent="Height"
+    WindowStartupLocation="CenterScreen"
+    mc:Ignorable="d">
+    <local_gui:AugmentedBorder Margin="10">
         <StackPanel>
-            <Image Width="211" MinHeight="50" x:Name="ImageQiqqaLogo" Margin="0,10,0,0" HorizontalAlignment="Center" />
-            <local_gui:AugmentedBorder Margin="10" >
+            <Image
+                x:Name="ImageQiqqaLogo"
+                Width="211"
+                MinHeight="50"
+                Margin="0,10,0,0"
+                HorizontalAlignment="Center" />
+            <local_gui:AugmentedBorder Margin="10">
                 <StackPanel Margin="10">
-                    <Button x:Name="ButtonGuest" Height="50" Content="Start Qiqqa (ESC)"/>
+                    <Button
+                        x:Name="ButtonGuest"
+                        Height="50"
+                        Content="Start Qiqqa (ESC)" />
                 </StackPanel>
             </local_gui:AugmentedBorder>
-            <local_gui:AugmentedInfoBarItemControl Margin="10" Header="Backup/Restore" Collapsed="false">
-                <StackPanel>
+            <local_gui:AugmentedInfoBarItemControl
+                Margin="10"
+                Collapsed="false"
+                Header="Qiqqa Base Path">
+                <StackPanel Margin="5">
+                    <TextBlock
+                        Margin="5,5,5,10"
+                        VerticalAlignment="Center"
+                        TextWrapping="Wrap">
+                        <Run Text="Your Qiqqa Databases are located at:" />
+                    </TextBlock>
+                    <TextBlock
+                        Margin="0,0,0,10"
+                        VerticalAlignment="Center"
+                        TextTrimming="CharacterEllipsis"
+                        TextWrapping="NoWrap">
+                        <Run
+                            x:Name="ObjQiqqaDatabaseLocation"
+                            FontWeight="Bold"
+                            Text="..."
+                            ToolTip="..." />
+                    </TextBlock>
                     <DockPanel Margin="5">
-                        <TextBlock TextWrapping="Wrap" VerticalAlignment="Center">
-                            <Run Text="Your Qiqqa Database is located at "/>
-                            <Run FontWeight="Bold" x:Name="ObjQiqqaDatabaseLocation"/>
-                            <Run Text="."/>
-                        </TextBlock>
+                        <Button
+                            x:Name="ButtonChangeBasePath"
+                            Height="20"
+                            Content="Change this path" />
                     </DockPanel>
+                </StackPanel>
+            </local_gui:AugmentedInfoBarItemControl>
+            <local_gui:AugmentedInfoBarItemControl
+                Margin="10"
+                Collapsed="false"
+                Header="Backup/Restore">
+                <StackPanel>
                     <DockPanel Margin="5">
-                        <local_gui:AugmentedButton DockPanel.Dock="Left" Width="100" Height="100" Margin="5,5,20,5" x:Name="ButtonBackup" />
-                        <TextBlock TextWrapping="Wrap" VerticalAlignment="Center">
-                            <Run Text="Press the Backup Button to backup your Qiqqa database to a .qiqqa_backup file. You can then transfer this file to safe storage or to a new computer to restore later."/>
+                        <local_gui:AugmentedButton
+                            x:Name="ButtonBackup"
+                            Width="100"
+                            Height="100"
+                            Margin="5,5,20,5"
+                            DockPanel.Dock="Left" />
+                        <TextBlock VerticalAlignment="Center" TextWrapping="Wrap">
+                            <Run Text="Press the Backup Button to backup your Qiqqa database to a .qiqqa_backup file. You can then transfer this file to safe storage or to a new computer to restore later." />
                         </TextBlock>
                     </DockPanel>
                     <DockPanel Margin="5">
-                        <local_gui:AugmentedButton DockPanel.Dock="Left" Width="100" Height="100" Margin="5,5,20,5" x:Name="ButtonRestore" />
-                        <TextBlock TextWrapping="Wrap" VerticalAlignment="Center">
-                            <Run Text="Press the Restore Button to restore a previous .qiqqa_backup file. Please note that this will overwrite your existing Qiqqa Database, so you may first want to do a Backup of your current Qiqqa Database..."/>
+                        <local_gui:AugmentedButton
+                            x:Name="ButtonRestore"
+                            Width="100"
+                            Height="100"
+                            Margin="5,5,20,5"
+                            DockPanel.Dock="Left" />
+                        <TextBlock VerticalAlignment="Center" TextWrapping="Wrap">
+                            <Run Text="Press the Restore Button to restore a previous .qiqqa_backup file. Please note that this will overwrite your existing Qiqqa Database, so you may first want to do a Backup of your current Qiqqa Database..." />
                         </TextBlock>
                     </DockPanel>
                 </StackPanel>
             </local_gui:AugmentedInfoBarItemControl>
-            <local_gui:AugmentedBorder Margin="5,10,5,5" x:Name="ProgressInfoWrapper" >
+            <local_gui:AugmentedBorder x:Name="ProgressInfoWrapper" Margin="5,10,5,5">
                 <StackPanel>
-                    <TextBlock x:Name="ProgressInfo" TextWrapping="Wrap" VerticalAlignment="Center">
+                    <TextBlock
+                        x:Name="ProgressInfo"
+                        VerticalAlignment="Center"
+                        TextWrapping="Wrap">
                         ...
                     </TextBlock>
                 </StackPanel>
diff --git a/Qiqqa/Main/LoginStuff/LoginWindow.xaml.cs b/Qiqqa/Main/LoginStuff/LoginWindow.xaml.cs
index 015728c18..84a5fb563 100644
--- a/Qiqqa/Main/LoginStuff/LoginWindow.xaml.cs
+++ b/Qiqqa/Main/LoginStuff/LoginWindow.xaml.cs
@@ -5,6 +5,7 @@
 using System.Windows.Input;
 using System.Windows.Media;
 using icons;
+using Microsoft.WindowsAPICodePack.Dialogs;
 using Qiqqa.Backups;
 using Qiqqa.Common.Configuration;
 using Qiqqa.Common.GUI;
@@ -56,6 +57,9 @@ public LoginWindow()
             ImageQiqqaLogo.Source = Icons.GetAppIcon(Icons.QiqqaLogoSmall);
 
             ObjQiqqaDatabaseLocation.Text = ConfigurationManager.Instance.BaseDirectoryForQiqqa;
+            ObjQiqqaDatabaseLocation.ToolTip = ConfigurationManager.Instance.BaseDirectoryForQiqqa;
+
+            ButtonChangeBasePath.Click += ButtonChangeBasePath_Click;
 
             ButtonRestore.Icon = Icons.GetAppIcon(Icons.Backup);
             ButtonRestore.IconWidth = ButtonRestore.IconHeight = 64;
@@ -77,6 +81,23 @@ public LoginWindow()
             KeyDown += LoginWindow_KeyDown;
         }
 
+        private void ButtonChangeBasePath_Click(object sender, RoutedEventArgs e)
+        {
+            using (CommonOpenFileDialog dialog = new CommonOpenFileDialog())
+            {
+                dialog.InitialDirectory = ConfigurationManager.Instance.BaseDirectoryForQiqqa;
+                dialog.IsFolderPicker = true;
+                if (dialog.ShowDialog() == CommonFileDialogResult.Ok)
+                {
+                    ConfigurationManager.Instance.BaseDirectoryForQiqqa = dialog.FileName;
+                    ObjQiqqaDatabaseLocation.Text = ConfigurationManager.Instance.BaseDirectoryForQiqqa;
+                    ObjQiqqaDatabaseLocation.ToolTip = ConfigurationManager.Instance.BaseDirectoryForQiqqa;
+
+                    Logging.Info("The user changed the Qiqqa Base directory to folder: {0}", dialog.FileName);
+                }
+            }
+        }
+
         private void UpdateStatusMessage(string message)
         {
             ProgressInfoWrapper.Visibility = String.IsNullOrEmpty(message) ? Visibility.Collapsed : Visibility.Visible;
@@ -99,11 +120,13 @@ private void LoginWindow_Closed(object sender, EventArgs e)
 
         private void ButtonBackup_Click(object sender, RoutedEventArgs e)
         {
+            ConfigurationManager.Instance.BaseDirectoryForQiqqaIsFixedFromNowOn = true;
             BackingUp.DoBackup();
         }
 
         private void ButtonRestore_Click(object sender, RoutedEventArgs e)
         {
+            ConfigurationManager.Instance.BaseDirectoryForQiqqaIsFixedFromNowOn = true;
             BackingUp.DoRestore();
         }
 
@@ -132,6 +155,7 @@ private void DoGuest()
         {
             IsEnabled = false;
 
+            ConfigurationManager.Instance.BaseDirectoryForQiqqaIsFixedFromNowOn = true;
             ConfigurationManager.Instance.ResetConfigurationRecordToGuest();
             CloseToContinue();
         }
@@ -162,6 +186,8 @@ private void StartMainApplication()
             WPFDoEvents.AssertThisCodeIsRunningInTheUIThread();
             WPFDoEvents.SetHourglassCursor();
 
+            ConfigurationManager.Instance.BaseDirectoryForQiqqaIsFixedFromNowOn = true;
+
             // Initialise the web browser
             try
             {
diff --git a/Qiqqa/Main/MainEntry.cs b/Qiqqa/Main/MainEntry.cs
index 35084877e..3ef6e735b 100644
--- a/Qiqqa/Main/MainEntry.cs
+++ b/Qiqqa/Main/MainEntry.cs
@@ -426,6 +426,7 @@ private static void application_DispatcherUnhandledException(object sender, Disp
         private static void RemarkOnException(Exception ex, bool potentially_fatal)
         {
             Logging.Error(ex, "RemarkOnException.....");
+
             if (!ShutdownableManager.Instance.IsShuttingDown)
             {
                 WPFDoEvents.InvokeInUIThread(() =>
@@ -441,12 +442,27 @@ private static void RemarkOnException_GUI_THREAD(Exception ex, bool potentially_
             try
             {
                 Logging.Error(ex, "RemarkOnException_GUI_THREAD...");
-                UnhandledExceptionMessageBox.DisplayException(ex);
+
+                // the garbage collection is not crucial for the functioning of the dialog itself, hence dump it into a worker thread.
+                SafeThreadPool.QueueUserWorkItem(o =>
+                {
+                    // Collect all generations of memory.
+                    GC.WaitForPendingFinalizers();
+                    GC.Collect(GC.MaxGeneration, GCCollectionMode.Forced, true, true);
+                });
+
+                bool isGDIfailureInXULrunner = ex.Message.Contains("A generic error occurred in GDI+");
                 const int EACCESS = unchecked((int)0x80004005);
-                if (ex.Message.Contains("A generic error occurred in GDI+") || ex.HResult == EACCESS)
+                if (isGDIfailureInXULrunner || ex.HResult == EACCESS)
                 {
                     potentially_fatal = false;
                 }
+
+                // do NOT display GDI+ errors as they are merely obnoxious and unresolvable anyway:
+                if (!isGDIfailureInXULrunner)
+                {
+                    UnhandledExceptionMessageBox.DisplayException(ex);
+                }
             }
             catch (Exception ex2)
             {
diff --git a/Utilities/Misc/Constants.cs b/Utilities/Misc/Constants.cs
index 95ef7a5bf..ba01fb82b 100644
--- a/Utilities/Misc/Constants.cs
+++ b/Utilities/Misc/Constants.cs
@@ -17,8 +17,8 @@ public class Constants
         // vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
         public const string QiqqaDevProjectDir = "W:/Projects/sites/library.visyond.gov/80/lib/tooling/qiqqa/Utilities/";
         public const string QiqqaDevSolutionDir = "W:/Projects/sites/library.visyond.gov/80/lib/tooling/qiqqa/";
-        public const string QiqqaDevTargetDir = "W:/Projects/sites/library.visyond.gov/80/lib/tooling/qiqqa/Utilities/bin/Debug/";
-        public const string QiqqaDevBuild = "Debug";
+        public const string QiqqaDevTargetDir = "W:/Projects/sites/library.visyond.gov/80/lib/tooling/qiqqa/Utilities/bin/Release/";
+        public const string QiqqaDevBuild = "Release";
         // ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
         // These 4 constants are live-patched by the Pre-build task (Qiqqa.Build/patch_settings_file.js)
 #endif