Yesterday Kaspersky blocked the Edge browser and also wouldn't load itself, after reporting application start up errors for the last week. So I rebooted and deinstalled and reinstalled Kaspersky, rebooted and then Edge loaded. Today the problem repeated itself, the only difference is Kaspersky was still working. To cure I followed the routine above disabling and reenabled Self Defence. This seemed to cure the problem. I would appear the problem is triggered by You Tube, which now features adverts mid stream, could this be triggering Self Defence, which shuts down Edge. The version is 21.7