Problem with Mac Installer Applications - application is damaged, can not be used to install macOS

[IWT]

It is likely that many of my fellow members will have come across this post from OS X Daily; but some won't and I think it is worthy of a careful read because the article applies to all Mac Installer Applications:

To Quote: "Many Mac users like to maintain a repository of MacOS installer packages for older versions of system software. For example, I (OS X Daily) have a collection of MacOS installers including for Mac OS X Snow Leopard, Mac OS X Mavericks, MacOS High Sierra, macOS Sierra, macOS Mojave, and MacOS Catalina. These can be used to build USB boot installers, restore systems, troubleshoot, perform clean installations of the various system software versions, perform upgrades to specific system software releases, and serve many other purposes. If you have a similar installer archive, it’s probably a good time to replace those installers with the new versions that won’t be expired"

Full article here: How to Fix “application is damaged, can’t be used to install macOS” Errors

Ian

 

[Rod]

Yes I've struck this issue, I only bother to keep the last macOS as a bootable USB thumb drive installer now. That has gotten me out of trouble a few times.


Sent from my iPhone using Mac-Forums

 

[krs]

. If you have a similar installer archive, it’s probably a good time to replace those installers with the new versions that won’t be expired"

I'm glad you posted this, but.....

How does one download installers of old macOS versions if Apple always pulls them when a new macOS becomes available?
I know that Randy posted links to older macOS installers a while back, but these were somewhat hidden and not on the Apple store as I understand it.

It was suggested that one can get around that issue if one turns off WiFi (or the connection to the net) when running the installer.
Makes some sense - anyone know if that is a work-a-round?

 

[TJack]

Never Mind

 

[TJack]

You might want to read the following at this link How to Fix a Damaged macOS Installer - MacRumors it gives you links to download previous versions of Macos and explains what is going one.

 

[krs]

Thanks,
Sounds like a great idea to have the latest version of the installers (with all the updates) that one may need to use.

I'm planning to download at least ElCapitan, High Sierra and Mojave.
I have one 2017 MacBook Air on ElCapitan which is not really officially supported by Apple, so I think if nothing else, that is a good one to have.

Why did you post "Never Mind" in your previous post - just wondering...

 

[Rod]

In my opinion you really only need the last one unless you are a repairer or collector of vintage model Macs.
If for example Catalina crashed on me for some reason and I had decided I wanted to return to Mojave I could boot, erase, format and restore to Mojave with my USB thumb drive installer of Mojave.
I could then restore my data from my CCC backup or Time Machine backup of Catalina.
Having done that if I decided I wanted to go back to High Sierra I could download the HS installer from my Purchases on the App Store and create a bootable installer from that and repeat the process above.
I can not imagine why I would want to go back further than that because that would be to an unsupported macOS and prior to APFS.
If I had a 2010 MBP that was still useable and the OS crashed I could download the installer on my current device and create a bootable installer when and if I needed it assuming it was not my only device there is no problem.

 

[IWT]

I'm glad you posted this, but.....

How does one download installers of old macOS versions if Apple always pulls them when a new macOS becomes available?
I know that Randy posted links to older macOS installers a while back, but these were somewhat hidden and not on the Apple store as I understand it.

It was suggested that one can get around that issue if one turns off WiFi (or the connection to the net) when running the installer.
Makes some sense - anyone know if that is a work-a-round?

The article I linked to gave details of where previous versions of the OS could be found.

And thank you for your kind words krs.

Ian

 

[ferrarr]

I keep all installers, that will run on my Mac Mini. I have from Yosemite to Catalina, but when I go into the macOS App Store, not one of the installers are listed with all my other "Purchases", so I am unable to download them again. If they still showed in the macOS App Store, I wouldn't have to keep a copy of them.

 

[krs]

I keep all installers, that will run on my Mac Mini. I have from Yosemite to Catalina, but when I go into the macOS App Store, not one of the installers are listed with all my other "Purchases", so I am unable to download them again. If they still showed in the macOS App Store, I wouldn't have to keep a copy of them.

Refurbished items one buys from Apple don't seem to show up in the Apple store either.
I bought a MacBook Air last year that came with Sierra and neither the computer or the software show up - I assume that is normal

 

[chscag]

I keep all installers, that will run on my Mac Mini. I have from Yosemite to Catalina, but when I go into the macOS App Store, not one of the installers are listed with all my other "Purchases", so I am unable to download them again. If they still showed in the macOS App Store, I wouldn't have to keep a copy of them.

@Bob:

Keep in mind that if the certificate to any version of macOS expires, it may not be possible to download it. That's why keeping the installers is important.

 

[krs]

@Bob:

Keep in mind that if the certificate to any version of macOS expires, it may not be possible to download it. That's why keeping the installers is important.

From the articles I read I thought the opposite was the case, like:
When one wants to use a previously downloaded installer (that is one already on ones Mac), the installer checks for a valid certificate at that time and if the certificate in the meantime has expired, one get that "Installer is damaged message"
So the installers that had been downloaded are useless.
Thus also the installer links in Mac Rumors which were supposed to be the latest version with a current valid certificate.
And also the comment if turning off WiFi gets around that.

 

[Randy B. Singer]

I just logged in to post on this very topic! Here is what I posed elsewhere:

If you were smart, and squirreled away a copy of the macOS installer program (maybe on a flash drive) in case you needed it...well, it probably won't work anymore because their certificates expired:

If you've got an old macOS install image, it will probably stop working today
If you've got an old macOS install image, it will probably stop working today

This article provides links to download installers with valid certificates:
How to Fix a Damaged macOS Installer - MacRumors

 

[chscag]

Thanks Randy for the clarification. The thread at MacRumors was an eye opener about the certificates expiring on Oct 24th of this year.

 

[krs]

I realize this is a thread from last year, but....

I just received a 500GB SSD I want to use to install Mojave on.
My USB Flash drive with Mojave doesn't work anymore because of the expired certificate.
If I follow the link here posted by Randy in post #13, I eventually get a message that the item is no longeravailable.

Is there another valid link to get Mojave?
I already downloaded it once (for the USB flash drive) so it doesn't show up swhen I go to the Apple store.

 

[Rod]

It should still be in your purchases but it could be "hidden". There is a show hidden button.

 

[Randy B. Singer]

...
My USB Flash drive with Mojave doesn't work anymore because of the expired certificate....

You can very quickly get your copy of Mojave working again, without having to download anything again, by following the directions under "Method 2" here:

How to Fix “application is damaged, can’t be used to install macOS” Errors



Step 1. Find the Installer for macOS Mojave on your USB flash drive

Step 2. Right click on the installer and click “Show Package Contents”.

Step 3. Click on folder named “Contents”.

Step 4. Click on the folder named “SharedSupport”.

Step 5. Delete the file named “InstallInfo.plist”.

Step 6. Enter your administer password to confirm.

Step 7. Now open the installer for MacOS Mojave again, it will run

 

[krs]

It should still be in your purchases but it could be "hidden". There is a show hidden button.

Thanks Rod,

I just looked at my Apple store purchases again. There is no "Show Hidden" button.
All it shows are older macOS up to El Capitan and a few other Mac applications and others.
I had also downloaded Sierra and High Sierra, neither one of those shows and when I do search for "macOS Mojave" all I get are apps related to Mojave.

 

[krs]

You can very quickly get your copy of Mojave working again, without having to download anything again, by following the directions under "Method 2" here:

How to Fix “application is damaged, can’t be used to install macOS” Errors



Step 1. Find the Installer for macOS Mojave on your USB flash drive

Step 2. Right click on the installer and click “Show Package Contents”.

Step 3. Click on folder named “Contents”.

Step 4. Click on the folder named “SharedSupport”.

Step 5. Delete the file named “InstallInfo.plist”.

Step 6. Enter your administer password to confirm.

Step 7. Now open the installer for MacOS Mojave again, it will run

Thanks Randy,

I remembered that those instructions were posted on this forum before, but trying to find them is not easy.

I'm going to start making my own reference file for ver useful items like that.

I haven't tried those instructions yet because last night as I was going to sleep I thought that maybe just resetting the date on my Mac might possibly do the trick.
But then, on the other hand, I thought that it couldn't possibly be that easy and Apple would be smarter.
However, Apple is rather sneaky here - the message that comes up is that the installer is corrupted (which in fact it isn't), but with a "Corrupted" file, people would just either try to repair it or trash it.
But since I learned-through this forum -that this error messages just comes up when the certificate on the installer is expired, I figured setting back the clock on the Mac is worth a try - and sure enough - that works as well!

I wonder if anyone else installed macOS that way, by resetting the clock, installing the OS, and then setting the clock properly again.

I'll try the "delete InstallInfo plist" later today - once Mojave is installed on my external SSD I want to transfer everything from El Capitan to Mojave and that would probably take a few hours so I want to do that over night.

 

[Randy B. Singer]

...

I wonder if anyone else installed macOS that way, by resetting the clock, installing the OS, and then setting the clock properly again....

Not only does it work and people have done it, I've recommended this procedure several times on this discussion group, and I believe much earlier in this very thread.