On my test environment I am running moodle 1.92+ (build 20080910), Windows Server 2k3 and mysql. I have noticed three issues so far with the certificate
1. The version of the certificate module on the moodle.org website does not work.
2. Getting the following error when I go into a certificate:
Notice: Undefined property: stdClass::$intro in Moodle\server\moodle\mod\certificate\lib.php on line 247
3. The force download option doesnt work.