.aic are cloud files that require an internect connection to access the cloud instance.
Hi @Rolando Riggio,
We are sorry to hear about your experience. As Kevin said, there are cloud documents that you are trying to open, and if you don't have an active internet connection or Illustrator & creative cloud services blocked in the system firewall, then this could happen. In such a case, you may go to https://assets.adobe.com/cloud-documents as suggested by Ton and download the file till the network issue is resolved.
Kindly update the discussion if you still need assistance with it. We'd be happy to help.
Thanks & Regards,
There was a file I was working on a while back but for some reason the thumbnail is now grayed out and I am having trouble opening it.
Try and duplicate it in the Cloud and then open it.