My sandbox app 'FridayApp' stopped and is currently not available. When I click on my app in the launchpad, i'm getting a dns-error: DNSPROBEFINISHED_NXDOMAIN. Fetching the application log from the dev portal is also not possible. Could it be that the cloud node is not available anymore?
I think that if this was a version 5 app that the app is no longer available, at least I got several mails over upgrading my sandbox apps to 6 before (I think June 1st) or they will be deleted.