AltGr key

Support for AltGr is limited in Synergy. Some users have good luck with remapping the Alt key to AltGr. You will have to use a config file for this, it is not supported in the GUI. Here are the instructions for that:

Start by exporting your current configuration, using File -> Save Configuration As.

Edit it using your favorite text editor, and find a section named Screens. Normally it looks like this:

 section: screens
   server:
      option1 = value
      option2 = value
      etc
   client:
      option1 = value
      option2 = value
      etc

What we want to do is add the option "alt=altgr" in the client section, like this:

 section: screens
   server:
      option1 = value
      option2 = value
      etc
   client:
      option1 = value
      option2 = value
      etc
      alt=altgr

Be sure to save this file someplace safe, where Synergy will be able to find it but it won't be messed with, and point Synergy to this file using the "Use existing configuration" option.

Some people have better results going the other way, using altgr=alt instead. Try this if you continue having troubles with the above example.

For recent versions of Synergy, at least partial success has been reported with using

      altgr = shift

for the clients in the Screen section of the Synergy configuration file (same place as above) instead.

See the GitHub issue here:

https://github.com/symless/synergy-core/issues/4411