We're sorry to hear about this. Please share a few more details on this, like how many pages your project has and whether it has a large number of images. Did you create it from the existing template, or did you create it from scratch?
Have you tried using the other suggested browsers (Safari, Microsoft Edge, and Google Chrome) to see if it makes a difference? Try clearing the browser's cache and cookies, and let us know how it goes. Also, would you mind sharing the project link to investigate further?
I still can't download any of my files as PDFs after months. It says there is an error. I have tried on different computers, using different internet servers, etc.
We'll be very happy to directly assist you with this. I'll send you a direct message, so that you could send the documents to us, to more directly investigate this.