Hello!
I tried to use the script to make Instances with the help of mekkablue–Insert Instances, but nothing happened. I know that I should see a pop-up window, but nothing comes up.
I also tried to quit and restart everything, but the same issue came up
You are in “Masters” tab that’s why, check “Exports” tab
Unfortunately, I already checked it and it is still not working.
Have you installed the modules from Window > Plugin Manager > Modules ?
Can you show me:
- the settings of Insert Instances?
- your Exports tab?
(Cmd-Opt-4 and then space bar to take a screenshot of the window only.)
I cannot see the settings of Insert Instances-window, that’s the issue I wrote about.
My Exports tab looks like this:
What is shown in Window > Macro Panel?
So the window does not show up, I didn’t get that. Then there must be an error message in the Macro window, as Sebastian mentions.
What happens if you type
print("Hello world!")
into the Macro Panel and run it?
Nothing happened. 
That means that your Python installation isn’t working. There are some forum threads about this. Have you restarted Glyphs since installing all the modules?
Little update here: I restarted everything, did a software update and now the window appears! It was probably a bug I think, and now with the new software, everything works well again.
Thank you all for your help and the time you spent with this!