Unable to update Plugins db for auth_saml2

Hey David - we've been having trouble updating the auth_saml2 plugin..

When submitting the upload form it sits there and eventually gives the "Something seems to be wrong with the Internet." moodle error.
Steps to reproduce:

Open this page:
https://moodle.org/plugins/addversion.php?id=1534

Upload the zip from this link:
https://github.com/catalyst/moodle-auth_saml2/archive/master.zip

Save the form and it dies

any chance you could take a look to see what's going on there in the backend at some point so we can update the plugin?