PDFCreator Pro crashes - cannot install latest version

Since today, PDFCreator Pro won't print anymore. It displays an error and quits. The Windows Eventlog listst two errors:

Application: PDFCreator.exe
Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: System.MissingMethodException

  • at pdfforge.PDFCreator.Editions.EditionBase.ProgramBase.Application_DispatcherUnhandledException(System.Object, System.Windows.Threading.DispatcherUnhandledExceptionEventArgs)*
  • at System.Windows.Threading.Dispatcher.CatchException(System.Exception)*
  • at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(System.Object, System.Delegate, System.Object, Int32, System.Delegate)*
  • at System.Windows.Threading.Dispatcher.LegacyInvokeImpl(System.Windows.Threading.DispatcherPriority, System.TimeSpan, System.Delegate, System.Object, Int32)*
  • at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr, Int32, IntPtr, IntPtr)*
  • at MS.Win32.UnsafeNativeMethods.DispatchMessage(System.Windows.Interop.MSG ByRef)*
  • at System.Windows.Threading.Dispatcher.PushFrameImpl(System.Windows.Threading.DispatcherFrame)*
  • at System.Windows.Application.RunDispatcher(System.Object)*
  • at System.Windows.Application.RunInternal(System.Windows.Window)*
  • at pdfforge.PDFCreator.Editions.EditionBase.ProgramBase.StartApplication(System.String[], System.Func`1<pdfforge.PDFCreator.Editions.EditionBase.Bootstrapper>)*
  • at pdfforge.PDFCreator.Editions.EditionBase.ProgramBase.Main(System.String[], System.Func`1<pdfforge.PDFCreator.Editions.EditionBase.Bootstrapper>)*
  • at pdfforge.PDFCreator.Editions.PDFCreatorProfessional.Program.Main(System.String[])*

and:

Faulting application name: PDFCreator.exe, version: 4.2.0.10, time stamp: 0x5f9ff435
Faulting module name: KERNELBASE.dll, version: 10.0.19041.1110, time stamp: 0x4809adf2
Exception code: 0xe0434352
Fault offset: 0x0000000000034ed9
Faulting process id: 0x3bec
Faulting application start time: 0x01d7890b2abfedf7
Faulting application path: C:\Program Files\PDFCreator\PDFCreator.exe
Faulting module path: C:\WINDOWS\System32\KERNELBASE.dll
Report Id: 0c0d46da-bfbe-4309-b508-0caf9641c5f1
*Faulting package full name: *
Faulting package-relative application ID:

Tried to repair it, but same errors appear in the Eventlog. So I downloaded the latest version and tried to install that one. Won't install either. Again two errors in the eventlog:

Application: PDFCreator-Professional-4_3_0-Setup.exe
Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: System.MissingMethodException

  • at PDFCreator_setup_bootstrapper.ZipAttachment.Extract()*
  • at PDFCreator_setup_bootstrapper.App.Main(System.String[])*

and:

Faulting application name: PDFCreator-Professional-4_3_0-Setup.exe, version: 4.3.0.35808, time stamp: 0x9526fde2
Faulting module name: KERNELBASE.dll, version: 10.0.19041.1110, time stamp: 0x4809adf2
Exception code: 0xe0434352
Fault offset: 0x0000000000034ed9
Faulting process id: 0x257c
Faulting application start time: 0x01d7893650587f1e
Faulting application path: H:\PDFCreator-Professional-4_3_0-Setup.exe
Faulting module path: C:\WINDOWS\System32\KERNELBASE.dll
Report Id: ea06b406-c23e-4419-b2a1-035318eaa213
*Faulting package full name: *
Faulting package-relative application ID:

The machine runs Windows 10 Pro 20H2 with latest updates installed.
How to fix this problem?