DO NOT TEST ON A LIVE/PRODUCTION SITE but rather on a copy of a production site with the owners permission.
Directions on how to test and what to test can be found at https://docs.joomla.org/Pre-Release_Testing.
For a list of bugs addressed by this release see https://github.com/joomla/joomla-cms/mi ... 0?closed=1.
The Production Team has asked that we specifically test the following (as well as the normal testing items - see doc above):
- Test the Joomla Update process (with the same file for example) and check the User -> Actions Log to verify it shows there. Link to packages https://github.com/joomla/joomla-cms/re ... /3.9.21-rc.
- Test the installation of new third-party extensions and check the Actions Log to verify those actions are there.
Again, DO NOT TEST ON A LIVE/PRODUCTION SITE! Rather, test on a copy of a website that you have permission to use.
Thank you for helping Production test this next release of Joomla.