UPDATE, revisiting this in 2024: SOLVED: Multiprocessing python module not working - #5 by JetXS
Revisiting this in 2023.
Note that using the multiprocessing library, you can use the multiprocessing.set_executable() method and pass the python exec of TouchDesigner.
Use app.binFolder + '/python.exe'
This should fix the popup.
In our future release you can also pass Path Objects.
Original issue, if it’s still occurring, could try to call multiprocessing.set_executable() first…
Best,
Michel