I have downloaded El Capitan from the link above. I created the bootable USB media. Gets all the way to the end of the install, the tells me that it cannot be verified, or that it may have been modified, errors out. I am stuck.

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Dalek2021 Author

Level 1

15 points

I have downloaded El Capitan from the link above. I created the bootable USB media. Gets all the way to the end of the install, the tells me that it cannot be verified, or that it may have been modified, errors out. I am stuck.

The links to download El Capitan and Yosemite will download the .dmg as advertised. I made the USB media and booted to it. Ran the installer, gets all the way to “less than a second remaining”, then errors out about not being verified, and that it could have been modified. Please help! Removing these from the App Store was a terrible idea

MacBook Pro

Posted on Feb 1, 2021 8:07 PM

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Answer 1

Feb 3, 2021 10:24 PM in response to Dalek2021

If you disconnect from both ethernet and WiFi while in the USB's recovery mode, you can use the Terminal date command to bypass most OS installation errors and certification issues.

In the menu bar, click Utilities

Then Terminal

Type "date <mmddHHMMccyy>"

Fill in the appropriate month, day, hour, minute, and four digit year you want.

In this case, my guesstimate for a good option would be January of 2016, since that was about three months after the initial release of OS X El Capitan.

So, based on that, your Terminal line should look like this (I'm just using a random time and day of the month, since it doesn't matter) "date 012217302016"

Press return

It should conform your changed date and time.

Then quit Terminal and proceed with your Mac OS X install.

I cannot 100% guarantee this will work, but it's never failed to clear up errors for me when installing older macOS/OSX versions yet!

Hope this helps.

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Answer 2

Dalek2021 Author

Level 1

15 points

Feb 10, 2021 11:31 AM in response to Lon3lyWanderer

You cannot be disconnected from the network with these new downloads. I disabled Wifi, and no Ethernet connected, and it will give an error that you must be connected to the Internet for it to proceed. Also, changing the date then running the install no longer works. It immediately throws an error when you start the install

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Answer 3

Eau Rouge

Level 8

42,602 points

Feb 3, 2021 9:31 PM in response to Dalek2021

In October 2019 the certificates for several OS's expired. Apple re-certificated these and posted them on their site.

Mac OS X El Capitan was removed from the App Store at this time and this newer method of downloading an

InstallMacOSX.dmg directly to the Downloads folder was introduced for Yosemite, El Capitan and an InstallOS.dmg

for macOS Sierra.

Click here,

How to get old versions of macOS – Apple Support

Go to Download OS and click on Mac OS X El Capitan

this will download the InstallMacOSX.dmg to your Downloads folder.

After it has downloaded open to the .pkg

and then create the Install OS X El Capitan.app.

I have downloaded and used this several times without incident.

I am now downloading again and will go through the process

and see if any errors occur.

In the meantime check everything on your end, 99 times out of 100

it is something at the users end.

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Answer 4

Eau Rouge

Level 8

42,602 points

Feb 4, 2021 5:08 AM in response to Dalek2021

So I downloaded the InstallMacOSX.dmg from the Download OS section in this link,

How to get old versions of macOS – Apple Support

Opened the InstallMacOSX.dmg all verified perfectly well.

Got the InstallMacOSX.pkg opened that to get Install OS X El Capitan.app

created a bootable USB.

Used the bootable USB to install El Capitan.

No problems whatsoever no need to change dates in Terminal.

All straight forward.

So something up at your end.

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Answer 5

Eau Rouge

Level 8

42,602 points

Feb 1, 2021 8:37 PM in response to Dalek2021

Once you downloaded the InstallMacOSX.dmg for El Capitan did you open it to the InstallMacOSX.pkg.

Double-clicking on the InstallMacOSX.pkg will open an installation window (this does not install El Capitan)

which will create the Install OS X El Capitan.app which you need to create the USB installer.

The installer app should be 6.2GBs in size, can you confirm that.

It may be if it cannot be verified then you may need to download the InstallMacOSX.dmg again.

Make sure your mac is connected to your router via cable, do not use the mac wile it is downloading

or any other devices that share the same internet connection.

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Answer 6

Dalek2021 Author

Level 1

15 points

Feb 2, 2021 8:26 AM in response to Eau Rouge

so I did disable Wifi, and connected to Ethernet to download. When opening the download, it scans it, and comes back “invalid checksum”. YOSEMITE does the same. You can skip this rather than letting it finish. I did open it, and clicked on “InstallMacOSX.pkg”. This part is around 7 mb. I do end up with the El Capitan.app. I then try to run the install. It eventually comes back saying “This copy of the Install OS X EL Capitan application can’t be verified. It may have been corrupted...”

what do I do?

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Answer 7

Dalek2021 Author

Level 1

15 points

Feb 2, 2021 2:13 PM in response to Eau Rouge

No. No over VPN. I called apple support, and spoke to an engineer. He suggested I download it on another machine and transfer it to the Mac. I did so, and did not get the bad checksum error. Opened the dmg file and clicked on the package. It ran and now have “ install OS X El Capitan” showing under applications. Ran this.. it gets to a point and Reboots , then continues to install. Runs for a while, then throws an error about the essentials package

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Answer 8

Dalek2021 Author

Level 1

15 points

Feb 3, 2021 7:21 PM in response to HWTech

I have already tried this today. Downloaded the dmg file again for El Capitan. No CRC or checksum error. Created USB media (Same article I used). Either way it gets all the way till the end, then gives error “This copy of the Install OS X EL Capitan application can’t be verified. It may have been corrupted...”. Same error as before. This all has to do with the original downloads they the App Store, the certificates expired. I talked with apple support yesterday(senior engineer). Sole removed El Capitan from the app store with the expired cert, and now you can only get it they the download of the dmg file.. only they are broke.. as in doesn’t work. However, I can download mountain Lion, run the dmg, and it installs (and ) because it came thru the App Store. There is nothing else I can do with this. Apple needs to fix their own images. Until then, this is hopeless

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Answer 9

HWTech

Level 9

60,794 points

Feb 3, 2021 10:03 PM in response to Dalek2021

Try using another USB stick especially another brand since the quality of USB sticks is extremely poor. Many USB sticks I have tested tend to flip bits from time to time. It has been a while since I downloaded the El Capitan installer, but I did use the new style downloaded as a .dmg file that needs to be extracted to the Applications folder without any issues. The USB stick is most likely the problem.

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Answer 10

HWTech

Level 9

60,794 points

Feb 11, 2021 5:10 PM in response to Dalek2021

To download the macOS installer you do need to be connected to the Internet, but once the installer is fully downloaded (about a 6GB file) you do not need to be connected to the Internet to make the bootable macOS USB installer or to install macOS using the bootable macOS USB installer.

For an older pre-2018 Mac you do not need to be connected to the Internet when using a bootable macOS USB installer unless perhaps you have some restrictions on the Mac from FindMy. For a 2018+ Mac you may need to be connected to the Internet to authenticate when booting from the USB drive or during initial setup after the install to possibly download extra required software.

Since you have an older Mac, then I agree with @Eau Rouge that you will have some sort of issue. Perhaps you are still booting into Recovery Mode instead of from the bootable macOS USB installer.

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