There are 2 places where we check that a SCORM package is valid:
mod_scorm_dndupload_handle
and validation in scorm/mod_form.php

We should use a single shared function to check for a valid package but I'd also like this to improve the handling in Moodle.
Some SCORM packages are zipped with an extra folder inside - we should automatically detect this and fix the package (ideally notifying the user.)
We should also allow for case insensitive search for imsmanifest.xml eg Imsmanifest.xml