High Sierra download damaged

https://support.apple.com/en-us/HT208969

is the only place you need to get High Sierra from. Make sure your data is backed up before installation.

Make sure your software is compatible.

This tip will walk you through more info.

https://discussions.apple.com/docs/DOC-10693

Note, if you try to download from Safari, some download links may not work. A later version of Chrome or Firefox that is able to run on Yosemite may be needed to download it.

The error message you are seeing really means the App Store has detected a copy of Install macOS High Sierra.app

or a partial copy. Look inside your Applications folder for Install macOS High Sierra.app. Move it to the Trash,

empty the Trash. Restart your mac, click on this link.

How to upgrade to macOS High Sierra - Apple Support

Go to Section 4 and click on Get macOS High Sierra.

This should open the App Store High Sierra page and it should say Get

click on that to begin the download.

Make sure your mac is connected to your router using a cabled connection if you can,

and do not use the mac while it is downloading, or any other devices that share the same internet

connection.

The download on Apple's website is for 10.6.8 only. Some have succeeded getting it on other operating systems.

My observation is this:

1. If you need 10.11, and your Mac shipped after 10.7, you are best off going to 10.12 directly.
2. If you need 10.11, and your Mac shipped prior to 10.7, but not prior to 10.6.3 you are in a bit of a limbo if you are missing the original discs, and it might work if you can get ahold of the original discs. If you didn't install the firmware for the restore partition, you are SOL when it comes to reformatting or replacing the hard drive without the original discs, or another Mac that you can clone 10.6.8 or later from over Target mode.
3. If your Mac shipped prior to 10.6.3 get the 10.6.3 retail, and run the 10.6.8 combo to get up to 10.11.

Regardless of what you do, you should backup any essential data first. Some Macs that get to 10.6.8 can only go as high as 10.6.8 or 10.7.5.

That is the place (the App Store) where the download is damaged...

Can Apple please fix this link or are there reasons it is showing as “damaged” and if so, is there anything on my end I can do to get it to function?

I am also trying to go from Yosemite to High Sierra on a late 2011 iMac

What is this answer to, and why the reference to 10.6.8, my post was to the original poster and concerns

downloading High Sierra, I have given them instructions.

In the original post the OP says they are on Yosemite, so they can upgrade directly to High Sierra

so no need for you to mention 10.6.8 or El Capitan.

So I am at a total loss why you responded to my post.

Personally, I wish Apple would have a version checker built-in to the installer that picks the necessary files to replace when upgrading, even if it isn't 10.6.8. The link on Apple's App Store page for 10.11 clearly says 10.6.8. What it does not say is what other operating systems they have tested and known it works on.

Because some of these "corrupted downloads" can only be because it is not seeing the right foundation to start from.