The error has something to do with Windows themes and Aero style. This is a bug that can cause the Windows Clock to appear black or invisible on the taskbar, making it difficult to read the time on your computer. Why is the Windows 10 clock missing or disappearing? How do I make the clock appear on the Windows 10 taskbar?.Why can’t I see the time and date on the taskbar?.How do I get the clock back on the desktop?.Check to see if the clock has been accidentally disabled.Here’s how to fix the problem of the clock disappearing or missing in Windows 10.Why is the Windows 10 clock missing or disappearing?.