List Editor install error

もしかしたら、以下の既知の問題が関係しているかもしれません。

Workaround

Once you have confirmed that you have "Download AppExchange Packages" system permission on the account,

Open a new incognito window, and close any other incognito windows with a Salesforce instance

1. Login to directly to your org

2. Go to the App Launcher, and click Visit AppExchange in the upper right corner

3. Search for the listing, and Click get it now

4. Login to AppExchange using your Salesforce production credentials

5. Choose where you want to install, production or sandbox

6. Complete the installation

If you are still having issues, contact Trailhead Support (https://trailhead.salesforce.com/help?support=home) and select Trailhead/Certification Account.

Getting an error that you don't have permission to install a package, and you have the correct permissions

https://trailblazer.salesforce.com/issues_view?id=a1p3A000000KQx1QAG&title=getting-an-error-that-you-don-t-have-permission-to-install-a-package-even-though-you-do-have-the-correct-permissions