I was able to install encore 6 on a new windows machine in 2021

[Michael Grenadier]

Not sure if this solution has been posted, but figured I'd give everybody a heads up in case it hasn't been.

This link will allow you to download encore 6

https://prodesigntools.com/adobe-cc-2018-direct-download-links.html

after you download it, you'll need to extract the file.  I had to install an extraction utility z-zip to extract the zip file and then extracted the contents of the zip file.

ran the installer, without issues, but when I tried to launch encore it said I had reached the maximum activations.  deactivated the other 2 computers I work on and still no go.

So I went back to the download link and downloaded and installed Premiere 2018.  It then asked me to update the activation for the windows machine, which I did.  Premiere 2018 launched and then

...

was able to launch encore6.  

No guarantees this will work for you, but worth a shot.  If you want Encore working on a newer machine, I'd do this asap cause you never know when adobe will change the rules.

[Michael Grenadier]

seems like adobe has disabled these direct download links.  I had to update my 2012 macbookpro to Mojave in order to install premiere 2021 and then I did a system migration from a clone of my previous install and of course premiere 2021 wouldn't open my project.  I'm working on a restoration of a film from the '80's and have to do captioning and dvd and blu-ray authoring so I guess I'm going to be bouncing back and forth between the old install and the new one.  in order to work with both encore 6 and premiere 2021.   

[Michael Grenadier]

actually managed to get it to install.  First, would not download in Chrome, but did in Safari and Firefox.  Then when I tried to run the installer it gave me an error message saying that elements were missing.   found this workaround

https://helpx.adobe.com/creative-cloud/kb/install-creative-suite-mac-os-sierra.html

and I've got what I need up and running   As I said before,. probably a good idea to download any installers for earlier versions that you might need in the future...  never know when adobe will pull the plug.   

[John T Smith]

>good idea to download any installers for earlier versions

Not only download...

IF/When you do have a download, be sure to copy it to AT LEAST one external device
-since Adobe does sometimes remove old versions from the server
-a usb flash drive or hard drive, or write to a DVD
-plus a text file containing your serial number

I use a Sata docking station and several 'bare' drives for backup
https://www.amazon.com/StarTech-com-External-docking-station-drives/dp/B00U8KSLA8/

[Michael Grenadier]

If you've got an active creative cloud subscription, you don't need a serial number.  But you do need to launch premiere 2019 or earlier (which is no longer supported) first.  Once you do that, you're asked to verify your CC subscription and you can then launch encore6 without issues and without a serial number.  I didn't have an encore 6 serial number.  I had an encore 5.5 one but had downloaded encore 6 when it was still available thru creative cloud.    And you're absolutely right, multiple backups are always a good idea.  I was talking to a co worker this morning and she was asking about her backup situation.  I told her every hard drive (including ssd's) will eventually fail.  It's not a question of if, but when.  turns out her backup drive is 10 years old....  Gotta say that docks can be problematic.  at least on a mac, they sometimes require multiple attempts before the drive mounts.  apparently this normal...  talked to someone at OWC years ago and they confirmed this.