Downloading updates failed:
- Cannot extract temporary://update-cache-48bc0127/basis.zip, not a valid archive. (this is one example)
basis.zip is downloaded/created in tmp directory (everything works fine, right up to the point it attempts to extract the archive)
zip/unzip works on command line. I can extract a zip file from Virtualmin GUI. A simple php script using extractTo() succeeds in decompressing a file.
I've verified the downloaded basis.zip file is a valid archive by extracting it in 7zip.
phpinfo(): ZIP enabled, version 1.15.6 (php7.4-zip)
One more thought: someone reported a similar issue with zip extension back in 2018. They run update.php and that solved it
https://forum.backdropcms.org/forum-topic/php-zip-extension-issue-192
To run update.php visit yoursite.com/update.php