Unable to sign received document

Hi,

I've received a document for signature but it won't let me sign it. The window opens and it continues saying "Preparing document" for hours on end.

I've tried signing in and out and back in with Adobe ID, with Adobe Enterprise login, from within incognito mode, from outside of incognito mode.

I've tried reaching out to Adobe but they say they won't support people who need to sign documents unless they are paid Adobe Sign customers (rather frustrating seeing as how I have a Creative Cloud subscription, which cost WAY more than an Adobe Sign subscription).

Anyways, does anyone know if some way for me to be able to sign these documents I've received?