Joomla 4.2.1: PHP Fatal error: Cannot declare class Lib_fieldsInstallerScript

[Sulpher]

Fresh Joomla 4.2.1. When installing Quatum 2.0.0, I get 500 error. Log:

[Wed Aug 31 15:56:20.451674 2022] [proxy_fcgi:error] [pid 284045:tid 140261661992704] [client 37.146.181.63:55136] AH01071: Got error 'PHP message: PHP Notice:  Trying to get property 'id' of non-object in /var/www/www/joomla4/libraries/src/Updater/Adapter/ExtensionAdapter.php on line 303', referer: https://joomla4/administrator/index.php

[Wed Aug 31 16:02:15.583173 2022] [proxy_fcgi:error] [pid 284045:tid 140261661992704] [client 37.146.181.63:55635] AH01071: Got error 'PHP message: PHP Fatal error:  Cannot declare class Lib_fieldsInstallerScript, because the name is already in use in /var/www/www/joomla4/tmp/install_630f5bd77de79/script.php on line 9', referer: https://joomla4/administrator/index.php?option=com_installer&view=install 

System Information (please complete the following information):

• Extensions version 2.0.0
• PHP version: 7.4
• Joomla 4.2.1