$> xpra attach --opengl=no --encoding=h264 --username=eric tcp:localhost:10000
2016-10-19 15:29:58,390 Xpra gtk2 client version 1.0-r14149 64-bit
2016-10-19 15:29:58,390  running on Linux Fedora 24 Twenty Four
2016-10-19 15:29:58,391 Warning: failed to import opencv:
2016-10-19 15:29:58,392  No module named cv2
2016-10-19 15:29:58,392  webcam forwarding is disabled
2016-10-19 15:29:58,575 GStreamer version 1.8.3 for Python 2.7.12 64-bit
2016-10-19 15:29:59,010  keyboard settings: rules=evdev, model=pc101, layout=fr
2016-10-19 15:29:59,011  desktop size is 1680x1050 with 1 screen:
2016-10-19 15:29:59,012   :0.0 (444x277 mm - DPI: 96x96) workarea: 1680x1016
2016-10-19 15:29:59,012     monitor 1 (474x296 mm - DPI: 90x90)
2016-10-19 15:29:59,548 Xpra X11 server version 1.0-r14149 64-bit
2016-10-19 15:29:59,549  running on Linux CentOS Linux 7.2.1511 Core
2016-10-19 15:29:59,549 enabled remote logging
2016-10-19 15:29:59,551 Attached to tcp:localhost:10000 (press Control-C to detach)

2016-10-19 15:30:36,590 server requested disconnect: server shutdown
[eric@lys ~]$ xpra attach --opengl=no --encoding=h264 --username=eric tcp:localhost:10000
2016-10-19 15:44:38,912 Xpra gtk2 client version 1.0-r14149 64-bit
2016-10-19 15:44:38,912  running on Linux Fedora 24 Twenty Four
2016-10-19 15:44:38,913 Warning: failed to import opencv:
2016-10-19 15:44:38,913  No module named cv2
2016-10-19 15:44:38,913  webcam forwarding is disabled
2016-10-19 15:44:39,086 GStreamer version 1.8.3 for Python 2.7.12 64-bit
2016-10-19 15:44:39,544  keyboard settings: rules=evdev, model=pc101, layout=fr
2016-10-19 15:44:39,545  desktop size is 1680x1050 with 1 screen:
2016-10-19 15:44:39,545   :0.0 (444x277 mm - DPI: 96x96) workarea: 1680x1016
2016-10-19 15:44:39,545     monitor 1 (474x296 mm - DPI: 90x90)
2016-10-19 15:44:40,073 Xpra X11 server version 1.0-r14149 64-bit
2016-10-19 15:44:40,073  running on Linux CentOS Linux 7.2.1511 Core
2016-10-19 15:44:40,074 enabled remote logging
2016-10-19 15:44:40,076 Attached to tcp:localhost:10000 (press Control-C to detach)

2016-10-19 15:45:21,716 server requested disconnect: server shutdown
[eric@lys ~]$ xpra attach --opengl=no --encoding=h264 --username=eric tcp:localhost:10000
2016-10-19 15:53:52,571 Xpra gtk2 client version 1.0-r14149 64-bit
2016-10-19 15:53:52,572  running on Linux Fedora 24 Twenty Four
2016-10-19 15:53:52,572 Warning: failed to import opencv:
2016-10-19 15:53:52,572  No module named cv2
2016-10-19 15:53:52,573  webcam forwarding is disabled
2016-10-19 15:53:52,753 GStreamer version 1.8.3 for Python 2.7.12 64-bit
2016-10-19 15:53:53,200  keyboard settings: rules=evdev, model=pc101, layout=fr
2016-10-19 15:53:53,202  desktop size is 1680x1050 with 1 screen:
2016-10-19 15:53:53,203   :0.0 (444x277 mm - DPI: 96x96) workarea: 1680x1016
2016-10-19 15:53:53,204     monitor 1 (474x296 mm - DPI: 90x90)
2016-10-19 15:53:53,756 Xpra X11 server version 1.0-r14149 64-bit
2016-10-19 15:53:53,756  running on Linux CentOS Linux 7.2.1511 Core
2016-10-19 15:53:53,757 enabled remote logging
2016-10-19 15:53:53,758 Attached to tcp:localhost:10000 (press Control-C to detach)

2016-10-19 15:54:19,504 downloaded 7395 bytes to application/pdf file for printing:
2016-10-19 15:54:19,504  '/home/eric/Downloads/2063309e720547981b7a1bdb85b93ff4306c5c78.pdf'
2016-10-19 15:54:19,505  sending 'Untitled1' to printer 'Xerox_Phaser_3250'
2016-10-19 15:54:19,507 Unhandled error while processing a 'send-file' packet from peer using <bound method XpraClient._process_send_file of gtk2.client>
Traceback (most recent call last):
  File "/usr/lib64/python2.7/site-packages/xpra/client/client_base.py", line 871, in process_packet
    handler(packet)
  File "/usr/lib64/python2.7/site-packages/xpra/net/file_transfer.py", line 278, in _process_send_file
    self.do_process_downloaded_file(filename, mimetype, printit, openit, filesize, options)
  File "/usr/lib64/python2.7/site-packages/xpra/net/file_transfer.py", line 284, in do_process_downloaded_file
    self._print_file(filename, mimetype, options)
  File "/usr/lib64/python2.7/site-packages/xpra/net/file_transfer.py", line 322, in _print_file
    job = print_files(printer, [filename], title, options)
  File "/usr/lib64/python2.7/site-packages/xpra/platform/pycups_printing.py", line 412, in print_files
    printpid = conn.printFiles(printer, filenames, title, actual_options)
TypeError: Keys and values must be strings
2016-10-19 15:56:57,513 server requested disconnect: server shutdown