diff --git a/gns3server/modules/vmware/vmware_vm.py b/gns3server/modules/vmware/vmware_vm.py
index 79cc2bf7..be1f352f 100644
--- a/gns3server/modules/vmware/vmware_vm.py
+++ b/gns3server/modules/vmware/vmware_vm.py
@@ -28,6 +28,7 @@ import tempfile
 
 from pkg_resources import parse_version
 from gns3server.ubridge.hypervisor import Hypervisor
+from gns3server.ubridge.ubridge_error import UbridgeError
 from gns3server.utils.telnet_server import TelnetServer
 from gns3server.utils.interfaces import get_windows_interfaces
 from collections import OrderedDict
@@ -357,6 +358,8 @@ class VMwareVM(BaseVM):
         if not ubridge_path or not os.path.isfile(ubridge_path):
             raise VMwareError("ubridge is necessary to start a VMware VM")
 
+        yield from self._start_ubridge()
+
         try:
             self._vmx_pairs = self.manager.parse_vmware_file(self._vmx_path)
         except OSError as e:
@@ -375,7 +378,6 @@ class VMwareVM(BaseVM):
         else:
             yield from self._control_vm("start")
 
-        yield from self._start_ubridge()
         for adapter_number in range(0, self._adapters):
             nio = self._ethernet_adapters[adapter_number].get_nio(0)
             if nio:
diff --git a/gns3server/modules/vpcs/vpcs_vm.py b/gns3server/modules/vpcs/vpcs_vm.py
index 6b8a878c..11074783 100644
--- a/gns3server/modules/vpcs/vpcs_vm.py
+++ b/gns3server/modules/vpcs/vpcs_vm.py
@@ -27,16 +27,16 @@ import signal
 import re
 import asyncio
 import shutil
-import gns3server.utils.asyncio
 
+from gns3server.utils.asyncio import wait_for_process_termination
+from gns3server.utils.asyncio import monitor_process
+from gns3server.utils.asyncio import subprocess_check_output
 from pkg_resources import parse_version
 from .vpcs_error import VPCSError
 from ..adapters.ethernet_adapter import EthernetAdapter
 from ..nios.nio_udp import NIOUDP
 from ..nios.nio_tap import NIOTAP
 from ..base_vm import BaseVM
-from ...utils.asyncio import subprocess_check_output, monitor_process
-
 
 import logging
 log = logging.getLogger(__name__)
@@ -268,7 +268,7 @@ class VPCSVM(BaseVM):
             self._terminate_process()
             if self._process.returncode is None:
                 try:
-                    yield from gns3server.utils.asyncio.wait_for_process_termination(self._process, timeout=3)
+                    yield from wait_for_process_termination(self._process, timeout=3)
                 except asyncio.TimeoutError:
                     if self._process.returncode is None:
                         log.warn("VPCS process {} is still running... killing it".format(self._process.pid))
diff --git a/gns3server/ubridge/hypervisor.py b/gns3server/ubridge/hypervisor.py
index fd765ac2..ed1b4e0e 100644
--- a/gns3server/ubridge/hypervisor.py
+++ b/gns3server/ubridge/hypervisor.py
@@ -23,9 +23,12 @@ import os
 import subprocess
 import asyncio
 import socket
+import re
 
+from pkg_resources import parse_version
 from gns3server.utils.asyncio import wait_for_process_termination
 from gns3server.utils.asyncio import monitor_process
+from gns3server.utils.asyncio import subprocess_check_output
 from .ubridge_hypervisor import UBridgeHypervisor
 from .ubridge_error import UbridgeError
 
@@ -114,14 +117,31 @@ class Hypervisor(UBridgeHypervisor):
 
         self._path = path
 
+    @asyncio.coroutine
+    def _check_ubridge_version(self):
+        """
+        Checks if the ubridge executable version is >= 0.9.1
+        """
+        try:
+            output = yield from subprocess_check_output(self._path, "-v", cwd=self._working_dir)
+            match = re.search("ubridge version ([0-9a-z\.]+)", output)
+            if match:
+                version = match.group(1)
+                if parse_version(version) < parse_version("0.9.1"):
+                    raise UbridgeError("uBridge executable version must be >= 0.9.1")
+            else:
+                raise UbridgeError("Could not determine uBridge version for {}".format(self._path))
+        except (OSError, subprocess.SubprocessError) as e:
+            raise UbridgeError("Error while looking for uBridge version: {}".format(e))
+
     @asyncio.coroutine
     def start(self):
         """
         Starts the uBridge hypervisor process.
         """
 
+        yield from self._check_ubridge_version()
         try:
-            # self._update_ubridge_config()
             command = self._build_command()
             log.info("starting ubridge: {}".format(command))
             self._stdout_file = os.path.join(self._working_dir, "ubridge.log")
diff --git a/gns3server/web/route.py b/gns3server/web/route.py
index 017e0fd0..bd78a120 100644
--- a/gns3server/web/route.py
+++ b/gns3server/web/route.py
@@ -26,6 +26,7 @@ import traceback
 log = logging.getLogger(__name__)
 
 from ..modules.vm_error import VMError
+from ..ubridge.ubridge_error import UbridgeError
 from .response import Response
 from ..crash_report import CrashReport
 from ..config import Config
@@ -179,7 +180,7 @@ class Route(object):
                     response = Response(request=request, route=route)
                     response.set_status(e.status)
                     response.json({"message": e.text, "status": e.status})
-                except VMError as e:
+                except (VMError, UbridgeError) as e:
                     log.error("VM error detected: {type}".format(type=type(e)), exc_info=1)
                     response = Response(request=request, route=route)
                     response.set_status(409)