In some cases, it can stay that way for as much as several minutes while the emulator program starts up.We don't know why this is, and it might not happen all the time, but we'll keep investigating.Is your browser running an extension that blocks connections?An example of an extension that blocks connections is the No Script extension for Firefox.Tenants in a cloud environment run services, such as Virtual Network Function instantiations, that may legitimately generate millions of packets per second.The hosting platform, hence, needs robust packet scheduling mechanisms that support these rates and, at the same time, provide isolation and dependable service guarantees under all load conditions.If you encounter a problem connecting to the emulator, visit the page Debugging issues in running the App Inventor Setup Tools and the emulator on Windows This gives a step-by-step procedure for attempting to isolate and ifix issues. The issues are the same for Mac OS and we will be publishing a Mac version of this document soon.) Please go through this procedure before filing an issue on the App Inventor forum.
The emulator should start on your computer, and connect to App Inventor so you can test your app and do live development.Part of the App Inventor software includes the App Inventor Companion app, running on the emulator.If App Inventor has trouble communicating with the emulator, it may ask you to restart the Companion.When you post to the forum, describe the results of the steps you tried, so that people who want to help you will have more information about where to begin.Here are some other things to investigate as part of your debugging.
Once the emulator gets past that, the screen will turn completely black and then come up with the Android home screen.