The error "HTTP Status 403: Access to the specified resource has been forbidden" normally indicates that access to the resource has been restricted in Canvas.
Staff:
Check the resource details in Canvas to ensure that access has not been date and time restricted or hidden. To check this, click on the Actions drop down menu to the right of the resource or folder and then click on Edit details. Check that the appropriate settings have been applied and amend where necessary.
Student:
Notify your tutor so that they can check that the resource hasn't been hidden or a date restriction set.