Where do I download MacOS Yosemite

Did you look at download sites like this :

h ttps://webforpc.com/mac/mac-os-x-10-10-yosemite-free-download-dmg/

Or this

h ttps://macpaw.com/how-to/download-old-macos-versions

I have never downgraded OS version, I don't know what are the risk of corrupting badly your data or the whole installation. take care.

May have a look here :

h ttps://www.macworld.co.uk/how-to/mac-software/how-remove-macos-high-sierra-downgrade-3581872/

Thank you but at the second site I am not able to see any download and the tips are not helpful for me.

What do you think of the first one? I have already seen a few of these sites, but I do not trust them that much.

Do you have a premium membership?

>I can not buy myself a membership for 99 dollars a year just to download MacOS Yosemite.

Doesn't matter....wouldn't help, as the only full download via Apple is as you note, via mac app store previous purchases.

Your best solution is to make HS work, and for that you'll need to visit Apple's public community support forums vs. risking off-topic here in the DevForums, thanks and good luck.

https://support.apple.com/

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Honestly, I would not be comfortable with the whole downgrade process.

In the last article, thjere is process which they claim can restore the initial installation. I would think this is the safest.

Could you have access to an Apple Store and ask them for advice ?