Notes All the tests must be done with PHP 8.1 The need to be performed with both MOODLE_401_STABLE and master. DEBUG DEVELOPER and display errors should be enabled. Before the patch (without the changes applied). Reproduce the problem. Log in as admin user. Go to Site administration > Users > Privacy and policies > Data requests. Create a new data request for a user and approve the request. (Log in as this user so that there is a record in the sessions table for this user.) Now from the CLI run: php admin/cli/adhoc_task.php --execute= 'tool_dataprivacy\task\process_data_request_task' Verify that you see "PHP Deprecated:  base64_decode(): Passing null to parameter #1 ($string) of type string is deprecated" warnings.   After the patch (with the changes). Confirm the fix. Log in as admin user. Go to Site administration > Users > Privacy and policies > Data requests. Create a new data request for a user and approve the request. (Log in as this user so that there is a record in the sessions table for this user.) Now from the CLI run: php admin/cli/adhoc_task.php --execute= 'tool_dataprivacy\task\process_data_request_task' Verify that you don't get any "PHP Deprecated" warnings any more.