PHP Warning with Divi and LM's Video theme

[aaronfc]

A PHP warning is generated when accessing Divi's editor when Learning Mode is enabled and "Video" theme is selected.

Originally reported by @renatho in #6451 (review)

Steps to reproduce

• Enable LM
• Choose "Video" theme (Sensei Pro)
• Install and enable Divi
• Enable Divi integration with Lessons
• Create a course, with some lessons.
• Go to edit the Lesson with Divi editor.

Expected

No PHP warning to appear.

Actual

The following PHP Warning is registered (confirm that WP_DEBUG is enabled):

[31-Jan-2023 21:49:54 UTC] PHP Warning:  Trying to access array offset on value of type null in /var/www/html/wp-includes/class-wp-block-supports.php on line 98

Extra context

@renathoc and me did some extra investigation and apparently this has to do with the fact that Video template contains a exceprt block.

We could "workaround" the warning by:

• Adding some excerpt to the lesson content (at the sidebar in the admin editor).
• Removing the <!-- wp:post-excerpt /--> block using the full site editor from the lesson template for Video theme.

Additionally, we have faced already issues related to "the excerpt" for Divi before and also for Yoast.

[m1r0]

Could someone please confirm that this is still an issue? I wasn't able to reproduce it.

I've tested on:

• Divi: 4.14.6
• Sensei LMS: trunk
• Sensei Pro: trunk
• WP: 6.2

[renatho]

Hi @m1r0! I'm still able to see the warning. I don't see it on the page anymore, but I can see it in the debug.log.

About versions, I'm with the same versions as you in Sensei LMS, Sensei Pro, and WP, but I needed to update the Divi to 4.20.4 because it wasn't working for some reason.

Did you activate the lessons here?

[m1r0]

It turned out the error is only visible on PHP 7.4+ but I was testing on PHP 7.2.

Thanks @renatho. 🙏