[4.x]: Physically removed asset breaks assets loading and any content page which includes it

[marcusgaius]

What happened?

Description

Getting error message "craft\services\Assets::getThumbUrl(): Return value must be of type string, null returned" when trying to open a cp page which should have access to an asset with broken index if the rendered preview is not present

Steps to reproduce

1. move or delete an asset from the indexed path
2. remove preview folders (not sure how those should be referred to, attaching a screenshot of them below)
3. try to access asset index, or element (including global) containing a field with the asset
   

Expected behavior

In Craft3, the thumbnail would be missing, and asset (image) wouldn't be there on the front, but the dashboard would work even without asset reindexing, showing empty thumbnails.

Actual behavior

The assets index page breaks, can't upload any additional assets without reindexing, the content pages relating to the missing asset break with critical error screen

Craft CMS version

4.0.0

PHP version

8.0.13|8.0.18

Operating system and version

Ubuntu 20.04|Ubuntu 20.04 (WSL2)

Database type and version

Ver 8.0.27-0ubuntu0.20.04.1 for Linux on x86_64 ((Ubuntu))|Ver 8.0.29-0ubuntu0.20.04.3 for Linux on x86_64 ((Ubuntu))

Image driver and version

GD 2.3.0|GD 2.3.0

Installed plugins and versions

• verbb/navigation 2.0.0
• spicywebau/craft-neo 3.x-dev
• craftcms/redactor 3.0.x-dev
• nystudio107/craft-seomatic 4.0.0-beta.8

[brandonkelly]

Thanks for reporting that! Fixed now for the next release.

[brandonkelly]

Craft 4.0.2 is out now with the fix for this.