Error Downloading macOS Mojave: We are unable to prepare your computer for macOS Mojave

[mikecalbreeeezy]

I'm getting an error when running the update. Any suggestions?

[taniguti]

This message must be shown when downloaded image's md5 check sum is not match what you expected.
Check parameter 7 of your macOS upgrade policy and also make sure if installer as you expected must be downloaded onto the Mac computer.