Error: Undefined offset: 3 at /var/www/nextcloud/lib/private/legacy/OC_Helper.php#548

[j-ed]

@kchoi

Is there a known date for when 20.0.2 will be released? Or is the only way this will be fixed sooner is to upgrade to a beta?

Have a look on the issue ticket and the applied fix. Usually it should be possible to get the file differences displayed so that you can patch your files on your own.