If you receive this message and Screen Capture is nowhere to be seen on your screen, it most probably means that the program is hidden to system tray.

It is usually located in the bottom-right corner of your screen.

Screen Capture icon may be either present in the visible area*,

or be among the hidden icons.

*Note that the product icon may vary from version to version. 

Right-click on the Screen Capture icon and select Show option. 

This should bring up the main program window.

If the icon is not there, press Ctrl+Shift+Esc keys to launch Task Manager and go to Processes tab. 

Find ScreenCapture.exe or a process called 'Movavi Screen Recorder' and click End, then try launching Screen Capture again.