After clicking "Copy" in UPS variables the UI crashes

[codiflow]

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• Completed below form
• Attached debug log file
• Copy output in File -> UPS Variable

WinNUT Version: v2.3.8988
Windows OS Version: Windows Server 2016 Essentials Build 14393

Describe the bug
After I click on "Copy" in UPS variables the UI crashes with the error message System.Runtime.InteropServices.ExternalException (0x800401D0): Der angeforderte Clipboard-Vorgang war nicht erfolgreich.. Full error log at the end of this issue.

The path mentioned in this error looks wrong (no user Glen on this machine):
C:\Users\Glen\Repositories\nutdotnet\WinNUT-Client\WinNUT_V2\WinNUT-Client\List_Var_Gui.vb

To Reproduce
Steps to reproduce the behavior:

1. Click on UPS variables
2. Click on Copy
3. Crash (Error message appears)
4. If I click on the X in the upper right corner the UI vanishes but the process is still running in the background. Need to shoot it with the task manager to be able to start the UI again.

Expected behavior
The UPS variable content should be copied to the clipboard.

Screenshots

Additional context
Error message:

System.Runtime.InteropServices.ExternalException (0x800401D0): Der angeforderte Clipboard-Vorgang war nicht erfolgreich.
   bei System.Windows.Forms.Clipboard.ThrowIfFailed(Int32 hr)
   bei System.Windows.Forms.Clipboard.SetDataObject(Object data, Boolean copy, Int32 retryTimes, Int32 retryDelay)
   bei System.Windows.Forms.Clipboard.SetText(String text, TextDataFormat format)
   bei System.Windows.Forms.Clipboard.SetText(String text)
   bei WinNUT_Client.List_Var_Gui.Btn_Clip_Click(Object sender, EventArgs e) in C:\Users\Glen\Repositories\nutdotnet\WinNUT-Client\WinNUT_V2\WinNUT-Client\List_Var_Gui.vb:Zeile 158.
   bei System.Windows.Forms.Control.OnClick(EventArgs e)
   bei System.Windows.Forms.Button.OnClick(EventArgs e)
   bei System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
   bei System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
   bei System.Windows.Forms.Control.WndProc(Message& m)
   bei System.Windows.Forms.ButtonBase.WndProc(Message& m)
   bei System.Windows.Forms.Button.WndProc(Message& m)
   bei System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   bei System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   bei System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)