I installed Hotkey list workflow, but there is an error during the execution after I type 'hk' in alfred.

Here is the debugger output:

[12:21:10.269] Hotkey List[Script Filter] Script with argv '(null)' finished
[12:21:10.270] ERROR: Hotkey List[Script Filter] Code 1: ./script.js: execution error: Error: Error: Can't get object. (-1728)

Do you have any idea what could cause this issue ?