Why is my Mac flashing a folder with a question mark?

Why is my Mac flashing a folder with a question mark? A folder with a flashing question mark means that your startup disk is no longer available or doesn’t contain a working Mac operating system. If the question mark is persistent, and your Mac does not start up normally: Press and hold the power button on your Mac for up to 10 seconds, until your Mac turns off.

A folder with a flashing question mark means that your startup disk is no longer available or doesn’t contain a working Mac operating system. If the question mark is persistent, and your Mac does not start up normally: Press and hold the power button on your Mac for up to 10 seconds, until your Mac turns off.