We have been running into this issue a lot lately. Your macbook will boot up to a black screen with a singe message: startup disk verification failed…
Very annoying, but luckily not hard to fix:
Shut down the computer
Press the on button and hold it until the computer says loading startup options
Click the cogwheel icon with “Options” (or Opties) underneath and click continue
Open the “Disk Utilities” (or Schijfhulpprogramma’s) the bottom option
Click “view” or “weergave” and choose “All devices” or “Alle apparaten”
On the left side you see 2 lists: internal and disk images. We will start with internal. Choose the lowest option in the list and at the top hit “First aid” or “EHBO”. Wait for it to finish
Continue up the list until you are at the top
Now do the same for the lower list “Disk images” or “Schijfkopieen”. Start at the bottom and go up. During these First Aid sessions your computer might freeze … don’t worry just wait.
When all is done hit the apple logo (top left) and reboot “Herstart”.
You will be prompted for your password .. enter it
After a while your computer should boot up normally! 🥳