exeption when minimizing window

Hello,

I am using Mathcad Prime 8.0.0.0, and since a few days i get an exception when minimizing the MathCad window.
Extract from the log file:
"Build Number : 2022.03.01.001
System Culture : en-US; Current UI Culture : de-DE
Architecture: x64
Application version is: PTC Mathcad Prime 8.0.0.0
Current license type is: CommercialSub



Exception data:
System.Object:
System.ArgumentException: Die Breite darf keine negative Zahl sein.
bei System.Windows.Rect.set_Width(Double value)
bei DevComponents.WpfRibbon.RibbonWindow.GetGlassClientRectangle(Rect r)
bei DevComponents.WpfRibbon.RibbonWindow.WmNcCalcSize(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
bei DevComponents.WpfRibbon.RibbonWindow.WindowMessageHandler(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
bei System.Windows.Interop.HwndSource.PublicHooksFilterMessage(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
bei MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
bei MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
bei System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
bei System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)
Betriebssystemname: Microsoft Windows 10 Enterprise
Betriebssystemversion: 10.0.19045 Nicht zutreffend Build 19045"

I can send the complete log file if needed.