[Bug] Linux: Exception error in compound creator in dwsim-classic

[einhander]

Describe the bug

Exception error in compound creator in dwsim-classic

To Reproduce Steps to reproduce the behavior:

1. Click on Create new compound

Desktop (please complete the following information):

• OS: Linux Debian 12 (testing)
• Version 8.1.0

Additional context Error text:

System.ArgumentNullException: Value cannot be null.
Parameter name: sourceToolStrip
  at System.Windows.Forms.ToolStripManager.RevertMerge (System.Windows.Forms.ToolStrip targetToolStrip, System.Windows.Forms.ToolStrip sourceToolStrip) [0x00017] in <a3daa9b84fd241a497578a25f68bc3c7>:0 
  at System.Windows.Forms.ToolStripManager.RevertMerge (System.Windows.Forms.ToolStrip targetToolStrip) [0x00018] in <a3daa9b84fd241a497578a25f68bc3c7>:0 
  at DWSIM.FormMain.FormParent_MdiChildActivate (System.Object sender, System.EventArgs e) [0x000d0] in <a94a418cbec341f380b05fd8bcc73f1e>:0 
  at System.Windows.Forms.Form.OnMdiChildActivate (System.EventArgs e) [0x0001c] in <a3daa9b84fd241a497578a25f68bc3c7>:0 
  at System.Windows.Forms.Form.ActivateMdiChild (System.Windows.Forms.Form form) [0x00018] in <a3daa9b84fd241a497578a25f68bc3c7>:0 
  at (wrapper remoting-invoke-with-check) System.Windows.Forms.Form.ActivateMdiChild(System.Windows.Forms.Form)
  at System.Windows.Forms.Form.SetVisibleCore (System.Boolean value) [0x0016c] in <a3daa9b84fd241a497578a25f68bc3c7>:0 
  at System.Windows.Forms.Control.set_Visible (System.Boolean value) [0x0000c] in <a3daa9b84fd241a497578a25f68bc3c7>:0 
  at System.Windows.Forms.Control.Show () [0x00000] in <a3daa9b84fd241a497578a25f68bc3c7>:0 
  at (wrapper remoting-invoke-with-check) System.Windows.Forms.Control.Show()
  at DWSIM.FormWelcome.LinkLabel4_LinkClicked_1 (System.Object sender, System.Windows.Forms.LinkLabelLinkClickedEventArgs e) [0x00041] in <a94a418cbec341f380b05fd8bcc73f1e>:0 
  at System.Windows.Forms.LinkLabel.OnLinkClicked (System.Windows.Forms.LinkLabelLinkClickedEventArgs e) [0x0001c] in <a3daa9b84fd241a497578a25f68bc3c7>:0 
  at System.Windows.Forms.LinkLabel.OnMouseUp (System.Windows.Forms.MouseEventArgs e) [0x0006f] in <a3daa9b84fd241a497578a25f68bc3c7>:0 
  at System.Windows.Forms.Control.WmLButtonUp (System.Windows.Forms.Message& m) [0x0007e] in <a3daa9b84fd241a497578a25f68bc3c7>:0 
  at System.Windows.Forms.Control.WndProc (System.Windows.Forms.Message& m) [0x0016f] in <a3daa9b84fd241a497578a25f68bc3c7>:0 
  at System.Windows.Forms.Label.WndProc (System.Windows.Forms.Message& m) [0x00025] in <a3daa9b84fd241a497578a25f68bc3c7>:0 
  at System.Windows.Forms.LinkLabel.WndProc (System.Windows.Forms.Message& msg) [0x00000] in <a3daa9b84fd241a497578a25f68bc3c7>:0 
  at System.Windows.Forms.Control+ControlWindowTarget.OnMessage (System.Windows.Forms.Message& m) [0x00000] in <a3daa9b84fd241a497578a25f68bc3c7>:0 
  at System.Windows.Forms.Control+ControlNativeWindow.WndProc (System.Windows.Forms.Message& m) [0x0000b] in <a3daa9b84fd241a497578a25f68bc3c7>:0 
  at System.Windows.Forms.NativeWindow.WndProc (System.IntPtr hWnd, System.Windows.Forms.Msg msg, System.IntPtr wParam, System.IntPtr lParam) [0x0008e] in <a3daa9b84fd241a497578a25f68bc3c7>:0