What is the size for the file you are working on? Have you checked with a different one?
If working on web, then you may use a different web browser and login on Adobe Document Cloud to share file.
If you are using any internet security software, then please turn it off for a while and then try accessing the service.
[Antivirus software can help protect your computer against viruses and other security threats. In most cases, you shouldn't disable your antivirus software. If you have to temporarily disable it to install or activate other software, you should re-enable it as soon as you're done.]