When I try to install macOS Monterey 12.4 I get the following error message- this copy of the Install macOS Monterey application is damaged, and can't be used to install macOS.
I have an iMac from late 2015 and am currently using Mojave 10.14.6.
iMac Line (2012 and Later)
IMHO, this is a two answer question.
first, are you attempting the download over wi-fi? when possible, you should perform macOS downloads with a wired ethernet connection. if this is not possible, (mac has no ethernet port) you should move the mac as close as possible to the router, and temporarily remove your other devices from the wi-fi. you need the most bandwidth going to the mac as you can get while downloading a macOS. I would trash the current Monterey installer and start over.
and second, some people have had issues trying to upgrade to monterey from any macOS prior to big sur. if it was me, i would try upgrading from Mojave to Catalina then Big Sur and only then on to Monterey.
the downloads for Catalina and big sur can be found here:
How to get old versions of macOS - Apple Support
you may also want to read these two pages first:
How to upgrade to Big Sur - User Tips
IMHO, this is a two answer question.
first, are you attempting the download over wi-fi? when possible, you should perform macOS downloads with a wired ethernet connection. if this is not possible, (mac has no ethernet port) you should move the mac as close as possible to the router, and temporarily remove your other devices from the wi-fi. you need the most bandwidth going to the mac as you can get while downloading a macOS. I would trash the current Monterey installer and start over.
and second, some people have had issues trying to upgrade to monterey from any macOS prior to big sur. if it was me, i would try upgrading from Mojave to Catalina then Big Sur and only then on to Monterey.
the downloads for Catalina and big sur can be found here:
How to get old versions of macOS - Apple Support
you may also want to read these two pages first:
How to upgrade to Big Sur - User Tips
Trouble installing Monterey 12.4
