I've tried the latest xpra+winswitch (1.0.2, 0.12.23) on ubuntu 16.04 but this was always the case also with previous versions. i've tried different video settings but even on grayscale and choose "low latency" the keyboard and screen still lags a little especially compared to using winswitch with NX. i'm using mostly in seamless mode , eclipse+terminal and in both NX is much smoother

I updated from the PPA last week and noticed the html5 client no longer works. I just get an empty white screen instead of windows loading. I was able to fix this by copying the /usr/share/xpra/www folder from a system that had a prior working install on it.

A hint may be here:

Files www.broken/connect.html and www/connect.html differ
Only in www.broken: connect.html.br
Only in www.broken: connect.html.gz
Common subdirectories: www.broken/css and www/css
Only in www.broken: favicon.ico.br
Only in www.broken: favicon.ico.gz
Files www.broken/favicon.png and www/favicon.png differ
Common subdirectories: www.broken/icons and www/icons
Files www.broken/index.html and www/index.html differ
Only in www.broken: index.html.br
Only in www.broken: index.html.gz
Common subdirectories: www.broken/js and www/js

When the client connects to the server, there are port forwarding and application startup errors.

[II] 2018/13/04 09:38:53.375532 ConchConnection.forward_port(12497,127.0.0.1,24065)
[II] 2018/13/04 09:39:31.742001 WinSwitchApplet.do_start_session(ServerConfig(desktop:158515233878749),Command(Mousepad: mousepad %F),xpra,None,{},False)
[II] 2018/13/04 09:39:31.742075 WinSwitchApplet.attention(Starting Mousepad,None)
[II] 2018/13/04 09:39:31.742134 StatusIconTray.animate_status_icon(Starting Mousepad,5) now=1523601571.74, tray_widget_animate_until=1523601505.56
[II] 2018/13/04 09:39:31.908503 ServerLink.add_port_forward(None,127.0.0.1,15071) adding new port forward
[II] 2018/13/04 09:39:31.908637 ConchConnection.forward_port(12498,127.0.0.1,15071)
[II] 2018/13/04 09:39:35.937471 ServerLineConnection.do_message(9e007000aad84b759b6f03735717ba4d,Session Mousepad Failed,Session failed to start,)
[II] 2018/13/04 09:39:54.238773 UI_Util.get_command_menu_entry(ServerConfig(desktop:158515233878749),Command(Gscriptor: gscriptor)) missing icon!
[II] 2018/13/04 09:39:54.239043 UI_Util.get_command_menu_entry(ServerConfig(desktop:158515233878749),Command(Jaxx: "/home/username/cryptowallets/jaxx-1.3.13-x86_64.AppImage" %U)) missing icon!
[II] 2018/13/04 09:39:54.240210 UI_Util.get_command_menu_entry(ServerConfig(desktop:158515233878749),Command(TurboVNC Viewer: /opt/TurboVNC/bin/vncviewer)) missing icon!
[II] 2018/13/04 09:39:54.241673 UI_Util.get_command_menu_entry(ServerConfig(desktop:158515233878749),Command(OpenCity: opencity)) missing icon!
[II] 2018/13/04 09:39:54.247141 UI_Util.get_command_menu_entry(ServerConfig(desktop:158515233878749),Command(aMule: amule %u)) missing icon!
[II] 2018/13/04 09:39:54.251555 UI_Util.get_command_menu_entry(ServerConfig(desktop:158515233878749),Command(Power Manager: xfce4-power-manager-settings)) missing icon!
[II] 2018/13/04 09:39:54.252573 UI_Util.get_command_menu_entry(ServerConfig(desktop:158515233878749),Command(TeXdoctk: texdoctk)) missing icon!
[II] 2018/13/04 09:39:54.253640 UI_Util.get_command_menu_entry(ServerConfig(desktop:158515233878749),Command(PyCrust: pycrust)) missing icon!
[II] 2018/13/04 09:39:54.255005 UI_Util.get_command_menu_entry(ServerConfig(desktop:158515233878749),Command(LMMS: env QT_X11_NO_NATIVE_MENUBAR=1 lmms %f)) missing icon!
[II] 2018/13/04 09:39:54.257128 UI_Util.get_command_menu_entry(ServerConfig(desktop:158515233878749),Command(GAdmin-Rsync: su-to-root -X -c /usr/sbin/gadmin-rsync)) missing icon!
[II] 2018/13/04 09:39:54.257361 UI_Util.get_command_menu_entry(ServerConfig(desktop:158515233878749),Command(GSmartControl: "/usr/bin/gsmartcontrol-root")) missing icon!
[II] 2018/13/04 09:39:54.259273 UI_Util.get_command_menu_entry(ServerConfig(desktop:158515233878749),Command(UNetbootin: /usr/bin/unetbootin)) missing icon!
[II] 2018/13/04 09:39:54.287996 WinSwitchApplet.do_start_session(ServerConfig(desktop:158515233878749),Desktop(Xfce Session: startxfce4),vnc,None,{},False)
[II] 2018/13/04 09:39:54.288073 WinSwitchApplet.attention(Starting Xfce Session,None)
[II] 2018/13/04 09:39:54.288128 StatusIconTray.animate_status_icon(Starting Xfce Session,5) now=1523601594.29, tray_widget_animate_until=1523601576.74
[II] 2018/13/04 09:39:54.547923 ServerLink.add_port_forward(None,127.0.0.1,16072) adding new port forward
[II] 2018/13/04 09:39:54.548147 ConchConnection.forward_port(12499,127.0.0.1,16072)
[II] 2018/13/04 09:39:55.599431 ProtocolHandler.do_encrypted_command(78296cadaa664db4903f9daf30f421f5e745774aa2ab268880acc074aa64e8b4be461c80a2b4e9d6cb5be604d2dc6d8d7...) decrypted command=send_session '4011ea7ccbbf4b4caa82f47d86bb0b98','9e007000aad84b759b6f03735717ba4d','base64:N2UyNGMwMmE= '
[II] 2018/13/04 09:39:55.599610 VNCClientUtil.attach(ServerConfig(desktop:158515233878749),ClientSession(:71 - vnc - connecting),127.0.0.1,12499)
[II] 2018/13/04 09:39:55.625427 VNCClientUtil.do_real_attach(ServerConfig(desktop:158515233878749),ClientSession(:71 - vnc - connecting),127.0.0.1,12499) saved password '#######' in /home/username/.winswitch/client/sessions/4011ea7ccbbf4b4caa82f47d86bb0b98/session.pass
[II] 2018/13/04 09:39:55.625532 VNCClientUtil.exec_client(ServerConfig(desktop:158515233878749),ClientSession(:71 - vnc - connecting),['/usr/bin/vncviewer', 'PasswordFile=/home/username/.winswitch/client/sessions/4011ea7ccbbf4b4caa82f47d86bb0b98/session.pass', 'name=Xfce Session on desktop', '127.0.0.1::12499'],None,None,available,True) starting SimpleLineProcess
[II] 2018/13/04 09:39:55.634440 VNCClientUtil.started(<winswitch.util.process_util.SimpleLineProcess instance at 0x7f5abbdf4dd0>) pid=None
[II] 2018/13/04 09:39:55.634966 SimpleLineProcess.start() process(['/usr/bin/vncviewer', 'PasswordFile=/home/username/.winswitch/client/sessions/4011ea7ccbbf4b4caa82f47d86bb0b98/session.pass', 'name=Xfce Session on desktop', '127.0.0.1::12499'])=<Process pid=6419 status=-1>
[II] 2018/13/04 09:39:56.214816 PortForwardChannel.__init__(<winswitch.net.conch_util.ConchConnection instance at 0x7f5ac06b5b48>,<function forwarding_ready at 0x7f5abbdd7578>,<function forwarding_failed at 0x7f5abbdd7aa0>)
[II] 2018/13/04 09:39:56.214968 ConchConnection.openChannel(<winswitch.net.conch_util.PortForwardChannel instance at 0x7f5abbdf4758>,'\x00\x00\x00\t127.0.0.1\x00\x00>\xc8\x00\x00\x00\t127.0.0.1\x00\x00\xcf\xde')
[II] 2018/13/04 09:39:56.215638 VNCClientUtil.handle_line_connected(ClientSession(:71 - vnc - connecting), CConn:       connected to host 127.0.0.1 port 12499) ServerConfig(desktop:158515233878749)
[II] 2018/13/04 09:39:56.215699 WinSwitchApplet.update_session_status(ServerConfig(desktop:158515233878749),ClientSession(:71 - vnc - connecting),connected)
[II] 2018/13/04 09:39:56.243185 ServerLink.forwarding_ready()