Try to access the Module/Files through a VPN tunnel (while not beeing logged in). If this works you are missing the Student role. This role is only granted to students. This role is automatically granted to students who use their account from the local computing centre (LDAP/RZ-Login).
If that still doesn't work, you can request access to the group of the Module. See “ Applying for Group membership to access restricted files ” . If you don't get an answer within a week or two, please contact the person responsible for the course.