diff --git a/gns3server/modules/iou/iou_vm.py b/gns3server/modules/iou/iou_vm.py
index e1ac73cf..9ebec9d2 100644
--- a/gns3server/modules/iou/iou_vm.py
+++ b/gns3server/modules/iou/iou_vm.py
@@ -1191,7 +1191,7 @@ class IOUVM(BaseVM):
         try:
             startup_config_content, private_config_content = nvram_export(nvram_content)
         except ValueError as e:
-            log.warning("Could not export configs from nvram file".format(nvram_file, e))
+            log.warning("Could not export configs from nvram file {}: {}".format(nvram_file, e))
             return None, None
 
         return startup_config_content, private_config_content
diff --git a/gns3server/modules/virtualbox/virtualbox_vm.py b/gns3server/modules/virtualbox/virtualbox_vm.py
index 40181b12..a3748414 100644
--- a/gns3server/modules/virtualbox/virtualbox_vm.py
+++ b/gns3server/modules/virtualbox/virtualbox_vm.py
@@ -879,6 +879,14 @@ class VirtualBoxVM(BaseVM):
                 yield from self._control_vm("nicproperty{} dest={}".format(adapter_number + 1, nio.rhost))
                 yield from self._control_vm("nicproperty{} dport={}".format(adapter_number + 1, nio.rport))
                 yield from self._control_vm("setlinkstate{} on".format(adapter_number + 1))
+
+                # check if the UDP tunnel has been correctly set
+                vm_info = yield from self._get_vm_info()
+                generic_driver_number = "generic{}".format(adapter_number + 1)
+                if generic_driver_number not in vm_info and vm_info[generic_driver_number] != "UDPTunnel":
+                    log.warning("UDP tunnel has not been set on nic: {}".format(adapter_number + 1))
+                    self.project.emit("log.warning", {"message": "UDP tunnel has not been set on nic: {}".format(adapter_number + 1)})
+
             elif isinstance(nio, NIONAT):
                 yield from self._control_vm("nic{} nat".format(adapter_number + 1))
                 yield from self._control_vm("setlinkstate{} on".format(adapter_number + 1))
diff --git a/gns3server/modules/vmware/__init__.py b/gns3server/modules/vmware/__init__.py
index 6f0212cf..b79cbebf 100644
--- a/gns3server/modules/vmware/__init__.py
+++ b/gns3server/modules/vmware/__init__.py
@@ -398,7 +398,7 @@ class VMware(BaseManager):
                         break
 
                 if vmlist_entry is not None:
-                    for name in inventory_pairs.keys():
+                    for name in inventory_pairs.copy().keys():
                         if name.startswith(vmlist_entry):
                             del inventory_pairs[name]