(difficulty: medium, requires teacher access to a course on a Moodle instance properly configured to run under IIS, regardless the Database server, and OS administrator access to the server hosting the instance, to change some registry settings) Required login redirect test. Publish a resource, e.g. a PDF, whose name is plain ASCII text in a restricted access course (no guest, no front page) and take note of its URL e.g. http://hostname/path/to/moodle/pluginfile.php/ <NNN>/mod_resource/content/<MMM>/<filename> ; Log out and clean your browser cache; Copy the URL above in your browser: you should be redirected to the login page and than, after a successful login, to the requested resource; UTF-8 encoding support test (out of scope but the main reason of this bug). Change the IIS configuration - if not already done at the time of creating a proper IIS configuration of the server hosting the Moodle instance - to support the UTF-8 encoding on Server Variables : reg add HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\w3svc\Parameters /v FastCGIUtf8ServerVariables /t REG_MULTI_SZ /d REQUEST_URI\0PATH_INFO iisreset Repeat the first test by adding a resource whose filename has been renamed using whatever UTF-8-based name you prefer e.g. by using Google Translate, keeping the original extension => これは動作します.txt.