However! This time I have a save that can replicate it!
https://www.dropbox.com/s/ob2c024osmgq4 ... 6.se1?dl=0

Go to the two GR units, select them and transfer the unit with 200 men to the one with 400 men, it will crash on clicking the transfer button.
See the end of this message for details on invoking
just-in-time (JIT) debugging instead of this dialog box.
************** Exception Text **************
System.IndexOutOfRangeException: Index was outside the bounds of the array.
at WindowsApplication1.CustomBitmapClass.DrawUnit(Int32 nr, Boolean forcehighlight, Graphics toG, Int32 tx, Int32 ty, Boolean ShowAttacker, Int32 OverruleHis, Int32 OverrulePower, Int32 OverruleRegime, Boolean FullRecon, Int32 ForceHideUnitMode, Boolean mostlyHidden) in G:\VR\VRDevelopment\WindowsApplication1\GUI\GraphicsAndSounds\Se1_CustomBitmapClass.vb:line 7455
at WindowsApplication1.BattlegroupWindowClass.View() in G:\VR\VRDevelopment\WindowsApplication1\GUI\Windows\NewWindows\Popups\BattlegroupWindowClass.vb:line 147
at WindowsApplication1.BattlegroupWindowClass.HandleMouseClick(Int32 x, Int32 y, Int32 b) in G:\VR\VRDevelopment\WindowsApplication1\GUI\Windows\NewWindows\Popups\BattlegroupWindowClass.vb:line 1321
at WindowsApplication1.MessagePopUpScreenClass2.HandleMouseClick(Int32 x, Int32 y, Int32 b) in G:\VR\VRDevelopment\WindowsApplication1\GUI\Screens\NewScreens\MessagePopUpScreenClass2.vb:line 183
at WindowsApplication1.Form1.Form1_Mousedown(Object sender, MouseEventArgs e) in G:\VR\VRDevelopment\WindowsApplication1\Form1.vb:line 1367
at System.Windows.Forms.Control.OnMouseDown(MouseEventArgs e)
at System.Windows.Forms.Control.WmMouseDown(Message& m, MouseButtons button, Int32 clicks)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.Form.WndProc(Message& m)
at WindowsApplication1.ImmoveableForm.WndProc(Message& m) in G:\VR\VRDevelopment\WindowsApplication1\ImmoveableForm.vb:line 67
at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
************** Loaded Assemblies **************
mscorlib
Assembly Version: 4.0.0.0
Win32 Version: 4.8.4180.0 built by: NET48REL1LAST_B
CodeBase: file:///C:/Windows/Microsoft.NET/Framework64/v4.0.30319/mscorlib.dll
----------------------------------------
WindowsApplication1
Assembly Version: 1.0.7458.17592
Win32 Version: 1.0.7458.17592
CodeBase: file:///C:/Games/Shadow%20Empire/ShadowEmpire.exe
----------------------------------------
Microsoft.VisualBasic
Assembly Version: 10.0.0.0
Win32 Version: 14.8.3752.0 built by: NET48REL1
CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/Microsoft.VisualBasic/v4.0_10.0.0.0__b03f5f7f11d50a3a/Microsoft.VisualBasic.dll
----------------------------------------
System
Assembly Version: 4.0.0.0
Win32 Version: 4.8.4001.0 built by: NET48REL1LAST_C
CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System/v4.0_4.0.0.0__b77a5c561934e089/System.dll
----------------------------------------
System.Core
Assembly Version: 4.0.0.0
Win32 Version: 4.8.4180.0 built by: NET48REL1LAST_B
CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Core/v4.0_4.0.0.0__b77a5c561934e089/System.Core.dll
----------------------------------------
System.Windows.Forms
Assembly Version: 4.0.0.0
Win32 Version: 4.8.4150.0 built by: NET48REL1LAST_C
CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Windows.Forms/v4.0_4.0.0.0__b77a5c561934e089/System.Windows.Forms.dll
----------------------------------------
System.Drawing
Assembly Version: 4.0.0.0
Win32 Version: 4.8.3752.0 built by: NET48REL1
CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Drawing/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Drawing.dll
----------------------------------------
System.Configuration
Assembly Version: 4.0.0.0
Win32 Version: 4.8.3752.0 built by: NET48REL1
CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Configuration/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Configuration.dll
----------------------------------------
System.Xml
Assembly Version: 4.0.0.0
Win32 Version: 4.8.3752.0 built by: NET48REL1
CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Xml/v4.0_4.0.0.0__b77a5c561934e089/System.Xml.dll
----------------------------------------
System.Runtime.Remoting
Assembly Version: 4.0.0.0
Win32 Version: 4.8.3752.0 built by: NET48REL1
CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Runtime.Remoting/v4.0_4.0.0.0__b77a5c561934e089/System.Runtime.Remoting.dll
----------------------------------------
irrKlang.NET4
Assembly Version: 1.0.6617.18847
Win32 Version:
CodeBase: file:///C:/Games/Shadow%20Empire/irrKlang.NET4.DLL
----------------------------------------
ICSharpCode.SharpZipLib
Assembly Version: 0.84.0.0
Win32 Version: 0.84.0.0
CodeBase: file:///C:/Games/Shadow%20Empire/ICSharpCode.SharpZipLib.DLL
----------------------------------------
************** JIT Debugging **************
To enable just-in-time (JIT) debugging, the .config file for this
application or computer (machine.config) must have the
jitDebugging value set in the system.windows.forms section.
The application must also be compiled with debugging
enabled.
For example:
<configuration>
<system.windows.forms jitDebugging="true" />
</configuration>
When JIT debugging is enabled, any unhandled exception
will be sent to the JIT debugger registered on the computer
rather than be handled by this dialog box.