Deleted memberships cause a page restricted by that membership to potentially be inaccessible

[brianhogg]

Reproduction Steps

1. Create two memberships
2. Enrol a student in both memberships
3. Create a page, enable Restrict this page, and selected the two created memberships
4. Move the first membership to the trash and delete it permanently
5. Login as the student and visit the page

Expected Behavior

I believe the page should be visible since the student is still in the second membership.

Actual Behavior

Page is not accessible with an error saying "You must belong to one of the following memberships to access this content: or A second membership"

Technical Notes

I think in llms_is_post_restricted_by_membership() we want to exclude checking for enrolments in memberships that aren't valid.

This issue has be recreated:

• [ ] Locally
• [ ] On a staging site
• [ ] On a production website
• [ ] With only LifterLMS and a default theme

[brianhogg]

This is now fixed. The multi-membership listing was reverted, and deleted memberships no longer prevent access from my testing.