Crash site when submitting settings

I have to delete the plugin with the file manager to recover the site. This is from error log:

[29-May-2024 11:28:13 UTC] PHP Fatal error: Uncaught TypeError: property_exists(): Argument #1 ($object_or_class) must be of type object|string, null given in ../wp-content/plugins/admin-site-enhancements/bootstrap.php:340

Happened on several sites. The above error is from a fresh WordPress installation.

Best regards.
Goran