When I install the latest version of Screencast Keys 3.0 from GitHub, and install the add-on, everything appears to be working fine. Screencast key tab appears.
When I enable I get the following error message, and I can see no fix.
When I install the latest version of Screencast Keys 3.0 from GitHub, and install the add-on, everything appears to be working fine. Screencast key tab appears.
When I enable I get the following error message, and I can see no fix.

You need to get the latest release Screencast Keys 3.5
Download here: https://github.com/nutti/Screencast-Keys/releases
Remove the already installed screencast, and install the new version.