Summary ========= If value of CUSTOM_COMPRESSION is not 0 or 1 then thinlinc client will hang when trying to login. Results ======== The Thinlinc Client will show 'Starting terminal client' with a black vncviewer window and nothing more happens. %TMP%/tlclient.log will show 2021-04-29T12:46:30: VNC command: "C:\Program Files\ThinLinc Client\vncviewer" -RemoteResize=1 -FullScreen -FullScreenAllMonitors=0 -FullscreenSystemKeys=1 -emulateMiddleButton=0 -FullColour=1 -LowColourLevel=2 -AutoSelect=1 -CustomCompressLevel=5 -CompressLevel=2 -QualityLevel=8 -MenuKey=F8 -PasswordFile=C:\Users\martin\AppData\Local\Temp\vncviewer3 -Shared=1 -DesktopSize=1920x1080 -geometry=1904x1011+8+31 127.0.0.1::52756 2021-04-29T12:46:30: vncviewer[E]: 2021-04-29T12:46:30: vncviewer[E]: ThinLinc Client 64-bit v4.12.1 2021-04-29T12:46:30: vncviewer[E]: Built on: 2021-02-03 09:06 2021-04-29T12:46:30: vncviewer[E]: Copyright (C) 1999-2021 TigerVNC Team and many others 2021-04-29T12:46:30: vncviewer[E]: See included EULA.txt for licensing details. 2021-04-29T12:46:30: vncviewer[E]: See http://www.cendio.com for information on ThinLinc. 2021-04-29T12:46:30: vncviewer[E]: 2021-04-29T12:46:30: vncviewer[E]: Thu Apr 29 12:46:30 2021 2021-04-29T12:46:30: vncviewer[E]: Config: Bool parameter CustomCompressLevel: invalid value '5' Howto reproduce ================ Start regedit and navigate to HKEY_CURRENT_USER\Software\Cendio\ThinLinc\tlclient\ right-click 'CUSTOM_COMPRESSION' and select 'Modifiy'. In 'Value data:' insert 5 and click OK. Try to login to a Thinlinc server. Expected results ================= Thinlinc client should not hang. A better error message about invalid configuration ?
Unfortunately this affects many settings, not just CUSTOM_COMPRESSION. There are a lot of things we pass on as-is to vncviewer. To make things more interesting, the behaviour is different on Windows on Linux. The hang is just on Windows. On Linux vncviewer correctly terminates and you get the "Your session lasted less than 10 seconds.".
