I have tried and failed to upload 500 MB documents. What is the permissible size of uploads to the cloud?
Since this was moved from an Acrobat forum just want to clarify if you are trying to use Creative Cloud Files website at https://assets.adobe.com and the file syncing that comes with the Creative Cloud desktop application; or if you are trying to use the Document Cloud at https://cloud.acrobat.com
From the Creative Cloud Desktop application FAQ is the question Is there a file size limit?:
With the Creative Cloud Desktop application, you can upload files up to 5 GB. If you attempt to upload anything larger, you may see some unexpected errors.
With the Creative Cloud website, you can upload files up to 1 GB. If you attempt to upload anything larger, you may see some unexpected upload failures.
I do not know what the upper limit is for the Document Cloud but you can ask at their forum here Document Cloud PDF services.