So I am working on a new application. Since today I can no longer preview the app in the sandbox. I get the following error "Whoops, something went wrong with deploying your app to the sandbox. Visit the developer portal to see the status of your app". I click the link and the developer portal thinks my app is running: Your app "Smart City Platform" is deployed in the Mendix Cloud. Currently running version 220.127.116.11 The log does not show any errors. How do I find the cause of what is happening and how do I fix it? And can it be caused by a different modeler version, I downloaded 5.12 today. It's different from this question in that I can see a version number. The answer there suggests to "redeploy from the modeler", but clicking "Run in Sandbox" another time is not helping.