In case useful to anyone: while trying to ‘Install Knime Extensions’, I was unable to access the Knime Partner Update Site 4.7. I was able to access the other (default) websites. (I am running Knime 4.7)
Many people had the same problem in 2023, but a solution was quickly found (press the Reload button), but this did not work for me. Upon clicking the Reload button I got this message:
Artifact not found: https://update.knime.com/partner/4.7/content.xml.xz.
I discovered that if I edit the URL from https to http, then reload, the URL/site works OK (I am able to access it).