You seriously waited for days with that on your screen? After a couple of hours, unless you are on a very slow dial-up internet connection, you should have killed it and started over again. It's hung-up.

Get your software and install it with this method, keep track of where the files ownload on your MAC so you can start the reinstall https://knowledge.autodesk.com/customer-service/account-management/software-downloads/previous-versi...