Two questions related to updating to latest PB with php8

I updated to latest PB with php8 and have two questions

I first updated to php8.1 and saw many warning when debug was set to true.
I was not sure from the documentation if php8.1 was also supported or “only” php8.0?

After updating PB to latest version with php8.0 I am seeing the error message “There was a problem with \Pressbooks\session_start(), headers already sent!” in the debug.log every time I load a page. But the site is working correctly as far as I can tell (Editing, Web view, Export, h5p, …). To find out where the message is coming from, I switched off all other plugins temporarily. This prevented new error entries in the debug.log. By reactivating the plugins one by one, I think I found the plugins that cause the error message.

• Logout Inactive Users
• Broken Link Checker
• Really Simple SSL
• Really Simple SSL Pro
• WP Mail SMTP Pro

I know that these plugins are not officially supported with PB. Nevertheless, they worked and still work perfectly, apart from the debug.log entries.

Does anybody else see the error message “There was a problem with \Pressbooks\session_start(), headers already sent!” in the debug.log? Any idea how to deal with the messages? Just ignore all the entries?

Thank you!

1 Like

Hi Thomas, we haven’t yet made Pressbooks fully compatible with PHP 8.1 and are seeing some deprecation notices in our CI test flow. See Make compatible with PHP 8.1 · Issue #3044 · pressbooks/pressbooks · GitHub for details. We’d like to work on this soon, however.

Thank you, Steel! I am using php8.0 now.