Traceback (most recent call last):


 "/home/tribler/.local/lib/python2.7/site-packages/twisted/web/server.py", line 199, in process

self.render(resrc)


 "/home/tribler/.local/lib/python2.7/site-packages/twisted/web/server.py", line 259, in render

body = resrc.render(self)


 "/home/tribler/.local/lib/python2.7/site-packages/twisted/web/resource.py", line 250, in render

return m(request)


 "/home/tribler/tudelft/tribler/Tribler/Core/Modules/restapi/downloads_endpoint.py", line 347, in render_PUT

payload = ChannelMetadataPayload.from_file(filename)


 "/home/tribler/tudelft/tribler/Tribler/Core/Modules/MetadataStore/serialization.py", line 166, in from_file

return cls.from_signed_blob(f.read())


 "/home/tribler/tudelft/tribler/Tribler/Core/Modules/MetadataStore/serialization.py", line 135, in from_signed_blob

return cls.from_signed_blob_with_offset(data, check_signature)[0]


 "/home/tribler/tudelft/tribler/Tribler/Core/Modules/MetadataStore/serialization.py", line 140, in from_signed_blob_with_offset

unpack_list, end_offset = default_serializer.unpack_multiple(cls.format_list, data, offset=offset)


 "/home/tribler/tudelft/tribler/Tribler/pyipv8/ipv8/messaging/serialization.py", line 328, in unpack_multiple

sys.exc_info()[2])


 "/home/tribler/tudelft/tribler/Tribler/pyipv8/ipv8/messaging/serialization.py", line 320, in unpack_multiple

unpacked, unpacked_size = self.unpack(format, data, current_offset)


 "/home/tribler/tudelft/tribler/Tribler/pyipv8/ipv8/messaging/serialization.py", line 297, in unpack

return self._packers[format].unpack_from(data, offset)


 "/home/tribler/tudelft/tribler/Tribler/pyipv8/ipv8/messaging/serialization.py", line 160, in unpack_from

out, = unpack_from('>%ds' % length, data, offset + self.format_size)
PackError: Could not pack item 9: varlenI

`Traceback (most recent call last):


 "/opt/node/repo/cohorteiot/iotill/printer/printer_comm.py", line 173, in _init_connection

self._printer = printer.Usb(w_usb_info[PRINT].get_vendor_id(),w_usb_info[PRINT].get_device_id(),None,0,w_usb_info[PRINT].get_endpoint_in_address(),w_usb_info[PRINT].get_endpoint_out_address())


 "/usr/local/lib/python3.6/dist-packages/python_escpos-3.0a9.dev26+g84a97e5-py3.6.egg/escpos/printer.py", line 53, in __init__

self.open(usb_args)


 "/usr/local/lib/python3.6/dist-packages/python_escpos-3.0a9.dev26+g84a97e5-py3.6.egg/escpos/printer.py", line 62, in open

raise USBNotFoundError("Device not found or cable not plugged in.")
escpos.exceptions.USBNotFoundError: USB device not found (Device not found or cable not plugged in.)`
