diff --git a/gns3server/modules/dynamips/dynamips_hypervisor.py b/gns3server/modules/dynamips/dynamips_hypervisor.py
index 0770ff63..7c93f775 100644
--- a/gns3server/modules/dynamips/dynamips_hypervisor.py
+++ b/gns3server/modules/dynamips/dynamips_hypervisor.py
@@ -474,8 +474,8 @@ class DynamipsHypervisor(object):
             log.debug("sending {}".format(command))
             self.socket.sendall(command.encode('utf-8'))
         except OSError as e:
-            raise DynamipsError("Lost communication with {host}:{port} :{error}"
-                                .format(host=self._host, port=self._port, error=e))
+            raise DynamipsError("Lost communication with {host}:{port} :{error}, Dynamips process running: {run}"
+                                .format(host=self._host, port=self._port, error=e, run=self.is_running()))
 
         # Now retrieve the result
         data = []
@@ -485,16 +485,16 @@ class DynamipsHypervisor(object):
                 chunk = self.socket.recv(1024)  # match to Dynamips' buffer size
                 buf += chunk.decode("utf-8")
             except OSError as e:
-                raise DynamipsError("Communication timed out with {host}:{port} :{error}"
-                                    .format(host=self._host, port=self._port, error=e))
+                raise DynamipsError("Communication timed out with {host}:{port} :{error}, Dynamips process running: {run}"
+                                    .format(host=self._host, port=self._port, error=e, run=self.is_running()))
 
             # If the buffer doesn't end in '\n' then we can't be done
             try:
                 if buf[-1] != '\n':
                     continue
             except IndexError:
-                raise DynamipsError("Could not communicate with {host}:{port}"
-                                    .format(host=self._host, port=self._port))
+                raise DynamipsError("Could not communicate with {host}:{port}, Dynamips process running: {run}"
+                                    .format(host=self._host, port=self._port, run=self.is_running()))
 
             data += buf.split('\r\n')
             if data[-1] == '':
@@ -502,8 +502,8 @@ class DynamipsHypervisor(object):
             buf = ''
 
             if len(data) == 0:
-                raise DynamipsError("no data returned from {host}:{port}"
-                                    .format(host=self._host, port=self._port))
+                raise DynamipsError("no data returned from {host}:{port}, Dynamips process running: {run}"
+                                    .format(host=self._host, port=self._port, run=self.is_running()))
 
             # Does it contain an error code?
             if self.error_re.search(data[-1]):
diff --git a/gns3server/modules/virtualbox/__init__.py b/gns3server/modules/virtualbox/__init__.py
index f84afd64..561c5131 100644
--- a/gns3server/modules/virtualbox/__init__.py
+++ b/gns3server/modules/virtualbox/__init__.py
@@ -724,7 +724,7 @@ class VirtualBox(IModule):
             result = subprocess.check_output(command, stderr=subprocess.STDOUT, timeout=30)
         except (OSError, subprocess.SubprocessError) as e:
             raise VirtualBoxError("Could not execute VBoxManage {}".format(e))
-        return result.decode("utf-8")
+        return result.decode("utf-8", errors="ignore")
 
     @IModule.route("virtualbox.vm_list")
     def vm_list(self, request):
diff --git a/gns3server/modules/virtualbox/virtualbox_vm.py b/gns3server/modules/virtualbox/virtualbox_vm.py
index 27ae75eb..deb34e1f 100644
--- a/gns3server/modules/virtualbox/virtualbox_vm.py
+++ b/gns3server/modules/virtualbox/virtualbox_vm.py
@@ -560,7 +560,7 @@ class VirtualBoxVM(object):
                 raise VirtualBoxError("{}".format(e))
         except (OSError, subprocess.SubprocessError) as e:
             raise VirtualBoxError("Could not execute VBoxManage: {}".format(e))
-        return result.decode("utf-8").splitlines()
+        return result.decode("utf-8", errors="ignore").splitlines()
 
     def _get_vm_info(self):
         """