i upgraded my Macbook Pro to Sierra and now have a black screen with a white folder flashing in the middle of the screen with a question mark on it

tania212 wrote:

Why has this happened and how do I fix it

According to: About the screens you see when your Mac starts up - Apple Support

"Folder with a question mark

If you see a folder with a question mark appear instead of the Apple logo, it means your Mac couldn't find a local or network-based startup disk. This can happen if the disk selected in the Startup Disk pane of System Preferences isn't available. Wait a few seconds to see if your Mac is able to locate the startup disk you specified.

If you still see a question mark after waiting a few seconds, use Startup Manager to start up your Mac, then select your startup disk from System Preferences.

If a question mark appears after you install a software update, select your startup disk again using macOS Recovery."

tania212 wrote:

Hi Ferd ll

Please excuse my ignorance, but how do I get to the Startup Manager from the screen with the white folder?

The link (use Startup Manager) If a flashing question mark appears when you start your Mac - Apple Support states:

"If your Mac starts up to a flashing question mark, but then doesn't continue starting up, try these steps.

1. Turn off your Mac by pressing and holding the power button for a few seconds.
2. Press the power button once to turn your Mac back on. Immediately press and hold the Command and R keys on your keyboard to start your Mac from macOS Recovery. Keep these two keys held down until you see an Apple logo or globe.
3. If prompted, select a Wi-Fi network to connect to the Internet as part of startup.
4. After the macOS Utilities window appears, choose Startup Disk from the Apple menu.
5. Select your startup disk, then click Restart.

If you don't see your startup disk in the Startup Disk window, close the window and try the next sections of this article."

You are welcome.

I followed the instructions given in order to get my Mac to work but the file with the question mark reappeared . What do I do now. Pls assist