For large applications, creating an isolate can take non-trivial time. Currently DevTools displays Loading... while it waits for the initial getVM response. This is a nice user experience while package:dwds creates the first isolate. Upon a refresh in which package:dwds sends an IsolateDestroy event, DevTools will properly clear out the content of the Debug page. However, it does not display any indication that it is waiting for an IsolateCreate event. Ideally DevTools displays the Loading... message again.