Today when I log into my web site and go to view an Joomla article (either core Joomla article or one that uses SPPB Editor), when I click the blue Preview button, the preview popup window appears, and I see the message:
The most recent request was denied because it had an invalid security token. Please refresh the page and try again.
This happens on all my Articles in the Joomla Article Manager (regular Joomla articles or SPPB ones) and it doesn't matter if they were created a long time ago, or just this past week.
This happens in all web browsers, even after cache and cookies deleted.
Any ideas why this would occur? Joomla! 3.9.24 / PHP 7.3 (also occurs with PHP 7.4)
Thanks for the clarification. Indeed, we have Shared Sessions enabled on quite a few of our Joomla sites, due to the use of another extension that must have Shared Sessions enabled to run. Hopefully one day you will find a way to make it work, as your plugin is really nice since we can preview changes before they are saved, which is so super-helpful!