This may help new Alfred 5 users, and might be a good note for the documentation?
I have only just upgraded from Alfred 4 to Alfred 5 (including the Powerpack), and I'm guessing my issue may have been because of that.
After installing the Quix workflow, I wasn't able to get it to do anything, either by hotkey or by using the quix command.
After checking the automation workflow, I noticed the first task had an error of 'Task Missing'. I double-clicked it, and the task pane in the left side of its config screen was empty.
The button underneat was labelled Get Tasks...
It was only after clicking that, that Alfred seemed to download its list of tasks and then the Quix Workflow picked up all its connections properly and everything seemed to work well after that.
Now that it's working as expected, I can already see how much time this will save, thank you!!