Incompatible Python workflow library
Note: Most workflows which contained a very old affected version of the alfred-workflow library should have been updated by now. If not, the following fix should still work.
Due to an incompatibility between macOS 10.12.4+ and a 3rd party library, Alfred-Workflow, Alfred 3.4.1+ doesn't load workflows containing older, affected versions of this library.
Disabling these workflows prevents the incompatibility from causing high CPU usage.
How to fix
Install and run the following workflow to automatically update Alfred-Workflow in any affected installed workflows.