Click Update Now to update your system’s firmware if an update is discovered.Allow your machine to check the servers for any updated information.Go to Apple > About This Mac in the menu bar.Therefore, we advise you to update your system to latest firmware as soon as possible to avoid any further startup problems. Firmware updates are rapidly made available by developers to address these problems as well as provide new security measures to your computer.

Your startup disc may malfunction due to compatibility difficulties and unstable firmware. Update macOS to avoid startup problems in the future.

Restarting your computer will make the process complete.

Accept the offer to do the test when prompted.

From the left sidebar, choose your startup disc.

The Disk Utility utility has a link to this. Mac Question Mark Folder, Your Mac’s First Aid feature checks your startup drive for any indications of underlying disc problems and, if necessary, attempts to resolve them.

Your computer will now boot from the chosen disc. If you attempt to boot from an SSD without an operating system installed, a flashing question mark appears to indicate that there is no bootable device.

Startup from your Mac OS X install disc and use Disk Utility to verify/repair the disk. Keep these held down until you hear the startup chime at least 2 or 3 times, then release them and let the machine boot.

Restart your computer after choosing the appropriate startup disc from the list. To do so, press the power button to turn on your Macbook and simultaneous hold down Option + Command + P + R.

Click on Apple > Startup Disk in the navigation bar.

You must thus use the macOS utilities/recovery window to access the system settings in order to investigate and resolve this issue. Instead, you will receive a question mark folder. You won’t be able to start the OS if the wrong drive is listed as a bootable disc in the System Preferences pane.

Mac Question Mark Folder, Choose the Proper Startup Disk.

Question mark mac startup