The outage in AWS S3, for the US-East region is negatively affecting many Qlik Sense Cloud users on Tuesday February 28, 2017.
Users are able to log in, but many are not able to open apps, open files, upload files.
You can go here to watch the status of this AWS issue: http://status.aws.amazon.com/
We are sorry for this inconvenience.
Director, Product Management, Qlik Cloud