Hyper-V with nested virtualization is only supported on Windows 10 Anniversary Update or later.

gns3server/controller/gns3vm/hyperv_gns3_vm.py

@@ -56,9 +56,13 @@ class HyperVGNS3VM(BaseGNS3VM):
         if not sys.platform.startswith("win"):
             raise GNS3VMError("Hyper-V is only supported on Windows")
 
-        if sys.getwindowsversion().platform_version[0] < 10:# or sys.getwindowsversion().build < 14393:
+        if sys.getwindowsversion().platform_version[0] < 10:
             raise GNS3VMError("Windows 10/Windows Server 2016 or a later version is required to run Hyper-V with nested virtualization enabled (version {} detected)".format(sys.getwindowsversion().platform_version[0]))
 
+        if sys.getwindowsversion().platform_version[0] == 10 and sys.getwindowsversion().platform_version[1] == 0:
+            if sys.getwindowsversion().platform_version[1] < 14393:
+                raise GNS3VMError("Hyper-V with nested virtualization is only supported on Windows 10 Anniversary Update (build 10.0.14393) or later")
+
         try:
             conn = wmi.WMI()
         except wmi.x_wmi as e:

gns3server/controller/project.py

@@ -744,8 +744,10 @@ class Project:
         os.remove(snapshot.path)
 
     async def close(self, ignore_notification=False):
-        if self._status == "closed" or self._loading:
-            log.debug("Closing project '{}' ignored because it is already closed or being loaded".format(self.name))
+        if self._status == "closed":
+            return
+        if self._loading:
+            log.warning("Closing project '{}' ignored because it is being loaded".format(self.name))
             return
         await self.stop_all()
         for compute in list(self._project_created_on_compute):