Release date: 16 February 2022.
- Tested: compatibility with WP 5.7.
- Improved: error handling.
The latest version of WordPress is currently WP 5.9. I have not stated compatibility with this version because I have not tested it thoroughly with block widgets: I downloaded the Classic Widgets plugin. Blipper Widget does work with WP 5.9 + Classic Widgets.
Testing with true blocks will happen soon.