Prerequisite: The scanning process will consume memory resources. I suggest increasing the memory limit in your PHP.ini to 256M, or more if needed. Run analysis Install PHPStan composer require --dev phpstan/phpstan Download : phpstan_mdl77342.neon and phpstan3rdparty.neon and put the files into Moodle's root folder. Run the analysis: php -dmemory_limit=256M vendor/bin/phpstan analyse --configuration phpstan_mdl77342.neon -vvv | tee result.txt Search for "Access to an undefined property". grep -i "Access to an undefined property" result.txt  Verify that you have an empty result. Testing repository plugins Check that repository plugins still work as expected by running the following QA tests Flickr - MDLQA-17553 Flickr public - MDLQA-17554 Amazon S3 - MDLQA-17702 WebDAV - MDLQA-17749 Wikimedia - MDLQA-17550 YouTube - MDLQA-17495 (Note that you may also pass these QA tests if they're working as expected) Log in as a user and open the user menu and click "Private files" Open the file picker and confirm that the " Recent files " functionality works. Confirm that the URL downloader functionality also works.