Bug fixes

Fix ignored file checking bug

Improved files checking process

Issue #3033171: Fatal error when opening preview modal

This release may have some implications for your theme -- if you have customized any of the API module CSS or theme templates, read the theme updates section on this issue:
#2958859: classes in different namespaces getting grouped together

Here's another alpha. If you'd like a beta, then please help with #2830988: [meta] 4.0.0 release roadmap.

Changes since 8.x-1.0-alpha4:

Alpha release snapshot.