Unfortunately we can't see what's going on in the background and there are no issues reported on https://status.mendix.com/ . I would recommend opening a ticket with Mendix support.
I faced a similar issue last month. I was trying to deploy my App on Cloud and repeatedly, I was getting similar message. I closed all my Apps and Studio Pro, logged off from Studio as well as other portals like Forums and Academy etc. I still had a Mendix Studio process running in the background in windows( could see via task manager), I had to manually kill it. I closed all my browser windows also. After that, I opened everything again and it worked fine.
I am not sure, if this happens due to some hanging processes in the background or what, but, its worth a try. Otherwise, anyways, you will need to open a ticket with Mendix Support
Data folder size is huge. Removed few data. Now deployment package is having size less than 1GB and able to deploy it in acceptance instance.
Your deployment package is probably too large as others have suggested. This issue usually occurs for me when there is a data snapshot present in the deployment package, as a data snapshot can easily be double the size of your actual project or more. Check to see if a data snapshot is present in the root file of the explorer and remove it before creating a new deployment package( IMO this is also just a general best practice ). I usually just keep a recent snapshot handy elsewhere on my computer just in case it’s needed for one reason or another.