Trying to upgrade from Sierra 10.12 to Mojave

[JDAA4]

I'm trying to upgrade from Sierra 10-12 to Mojave. I get this error message "You may not install to this volume because it has legacy FileVault users". I'm using MacBook Pro (Retina, 15-inch, Mid 2014)
Processor 2.8 GHz Intel Cor i7
Memory 16 GB 1600 MHz DDR3
Startup Disk Macintosh HD
Graphics Intel Iris Pro 1536 MB

I'm very computer illiterate.

 

[CoastalOR]

Assuming you have FileVault turned on, then I would recommend turning it off, then wait for the decryption to finish, then try to upgrade to Mojave.
https://support.apple.com/en-us/HT204837

Make sure you have a backup of your current system before any OS upgrade in case there is a problem during the upgrade.

 

[JDAA4]

Assuming you have FileVault turned on, then I would recommend turning it off, then wait for the decryption to finish, then try to upgrade to Mojave.
https://support.apple.com/en-us/HT204837

Make sure you have a backup of your current system before any OS upgrade in case there is a problem during the upgrade.

Thank you. I was able to update with no problem after your advice.