I can't install macOS Mojave because this copy of the Install macOS Mojave.app application is damaged I've been trying to upgrade my Mac from High Sierra to Mojave, but I keep getting the error below.



I rang Apple support and they told me to wait a while and try downloading it again from the App Store. I've now done this 2 times and continue to get the same error. 

I spoke with Apple again and they said to wait a while and try installing it again. It's now been two days and I've rebooted my Mac a number of times, and have attempted installation many times. 

I also tried installing all other software updates in case that was a factor. They all updated fine without any problem. The only thing I can't do is get the Mojave installer to run because it is apparently "damaged".

Maybe this is the universe telling me not to upgrade and I should give up, but now I'm here to ask you good folk.

Can someone kindly suggest other options for me?
go to the applications, and delete the "install macOS Mojave" file, and then you are able to re-download the file in app store. Just try to download it again. That's all.