If the RoboServer is installed on a headless linux server, Fonts have to be installed for the webkit robots to work properly.
One signal that fonts might be missing is if robots are throwing "Tag Finder Errors" when run on the headless linux server but work without issue when run on a Windows server or linux with user interface. Also, if the robot is taking any print screens of the pages, all text will be missing from the images.
Instructions for installing fonts for CentOS / RedHat:
Instructions for installing fonts for Ubuntu:
Ubuntu's fonts download page:
Note: Kapow doesn't require a certain set of fonts. As long as at least one type of fonts is installed, the robots will be able to run.
Keywords: headless linux, Kapow webkit, Kapow, Robotic Process Automation