macOS Sierra bootable USB

Have you recently downloaded a copy of the macOS Sierra installer .dmg called InstallOS.dmg,

and have you then processed that to get the Install macOS Sierra.app which appears in your

Applications folder.

There is a problem with making a bootable USB installer with the Install macOS Sierra.app

where it returns an error Volumes/<USBname> is not a valid mount point. There is a workaround.

With Install macOS Sierra.app in your Applications folder open Terminal.

Paste in this command

sudo plutil -replace CFBundleShortVersionString -string "12.6.03" /Applications/Install\ macOS\ Sierra.app/Contents/Info.plist

press return

enter your password

press return

Now paste in the createinstallmedia command for Sierra where MyVolume can be replaced with the name of your USB stick

If your USB name has more than one word separated by spaces you would need to type it in as

/The\ USB\ Name

sudo /Applications/Install\ macOS\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume --applicationpath /Applications/Install\ macOS\ Sierra.app

press return 

follow the prompts

The process takes around 30 minutes to complete, be patient, Terminal will look like it is not

doing anything but it is.

When it has completed you can eject the USB, and insert it directly to your mac.

Restart the mac while pressing the option/ alt key.

In a minute or two you will see the Startup Manager select the USB and press Return.

After the mac has booted to the USB you will see a Utilities screen.

Select Disk Utility and press Continue.

Highlight the Disk in the left hand panel, not any indented Volumes.

Click Erase.

Format: Mac OS Extended (Journaled)

Scheme: GUID Partition Map

Click Erase.

When Done quit Disk Utility.

Select Install OS press Continue

The installation process should start follow the prompts.

Thank you for your help. It works.