The message prompts "The current input timing is not supported by the monitor display. Please change your input timing to 1280x1024@60HZ or any other monitor listed timing as per the monitor specifications" in the monitor.

I changed the display resolution from the Control Panel and adjusted the Intel Graphics Control Panel as well but still doesnt work. 

Reference:

HP Spectre Folio

Windows 10

Intel (R) UHD Graphics 615

PC USB C port --> USB C TO VGA cable --> VGA monitor port
 

Hope you can help me. Thanks!