After the May 2015 update to the .NET Framework, many users running Perspective 4.5 or earlier on Windows 7, 8, or 8.1 have experienced an error message when using the calendar feature to select dates.
"Source:System.Windows.Forms Operation is not valid due to the current state of the object.Stack Trace: at System.Windows.Forms.MonthCalendar.WndProc(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)"
Though clicking Continue when this error message appears doesn’t affect any data, the issue was resolved in Perspective 4.6, so upgrading to version 4.6 or later will prevent the error message from appearing.
If you don’t want to upgrade your version of Perspective, you may also:
- Enter dates into various fields by typing them on your keyboard.
- Click Continue each time the error message appears and continue to work.
- Uninstall the following Windows updates:
- For Windows 7: KB30232222
- For Windows 8 and 8.1: KB3023224