Could not get the VM list from the server: uncaught exception <class 'gns3server.modules.virtualbox.virtualbox_error.VirtualBoxError'>: No vboxwrapper path has been configured
Traceback (most recent call last):
File "/usr/local/lib/python3.4/dist-packages/gns3_server-1.0beta1-py3.4.egg/gns3server/modules/base.py", line 275, in _decode_request
self.modules[self.name][destination](self, params)
File "/usr/local/lib/python3.4/dist-packages/gns3_server-1.0beta1-py3.4.egg/gns3server/modules/virtualbox/__init__.py", line 751, in vm_list
self._start_vbox_service()
File "/usr/local/lib/python3.4/dist-packages/gns3_server-1.0beta1-py3.4.egg/gns3server/modules/virtualbox/__init__.py", line 127, in _start_vbox_service
raise VirtualBoxError("No vboxwrapper path has been configured")
gns3server.modules.virtualbox.virtualbox_error.VirtualBoxError: No vboxwrapper path has been configured

Check out this post. Might help solve your issue.
http://forum.gns3.net/post34294.html#p34314