How to solve "An error occured while verifying firmware" when updating to Mojave? I just bought an early 2015 MacBook Pro that comes with macOS sierra. I want to update it to Mojave so i could run newer version of Xcode. But unfortunately i got this error everytime i tried to update it:


  An error occured while verifying firmware.


I tried to update it to High Sierra, but it does the same thing.

I borrowed my friend's bootable USB with High Sierra and change my SSD format to APFS, but it still gave me that error. I've tried to google for an answer and one of the forums that discussing this issue tells the original poster that it might have a problem regarding the logic board of the MBP. Which kinda freaked me out.

Why is this happening? And what should i do? Because i just switched to a mac from a windows laptop, so i still have zero knowledge about macos.
I prefer to get my installers from Apple, especially when I get an error with the download like you may have. 


https://support.apple.com/en-us/HT201314


If your Mac is operational, absolutely get a good backup now before you attempt another install. That way you can escalate to an erase install which removes all your existing system and data and ensures if that install fails you know your hardware or network is the cause of the error. 

Since yoU don’t need a backup, I would do the erase install and go to the latest possible. 


https://support.apple.com/en-us/HT204904 (explains how to steer which version installs from recovery)
https://support.apple.com/en-us/HT201255 (explains the overall process)
https://support.apple.com/en-us/HT208496 (erase steps - read last, start here)