Set up a Moodle site with working Unoconv with pathtounoconv correctly set up. View the Unoconv test PDF: Browse to Site administration → Plugins → Document converters → Manage document converters , and click Settings for the Unoconv entry. Click Test unoconv path . Click Download the converted pdf test file. The test PDF ("This is a test") should appear. Delete the file conversion row: DELETE FROM mdl_file_conversion WHERE sourcefileid IN (SELECT id FROM mdl_files WHERE filename = 'unoconv_test.docx' AND filearea = 'fileconverter_unoconv'); This simulates the actions of \core_files\task\conversion_cleanup_task which would delete the row after one week. View the Unoconv test PDF by repeating the steps under step 2. Expected results After step 4, the test PDF should appear. No error messages should appear.