Q:

Autokey won't start

I installed autokey-gtk application but it won't start.  When I run it from terminal it will write a message:
Xlib.protocol.request. QueryExtension

but that's all.  The application won't start. 
Do you know what is wrong? 

A:

8 years leater, but hopefully still useful for someone.  From https://askubuntu.com/a/304834:

The first time you launch AutoKey, it will start the service in the
  background (the notification icon hasn't been updated for unity, so
  there's no visual indication).  Once it's running, you can bring up the
  configuration interface by running the launcher again

So, Ubuntu 19.04 I have to type autokey twice from terminal.  From dash once is sufficient. 
Perhaps also useful: if Autokey does not start at login but you still selected that option, look at https://github.com/autokey/autokey/issues/149 

