Thanks for the response. Unfortunately removing /bin/sh made no difference (I think I tried with and without it - should have mentioned that). Looking at the return from the system call it’s 32512, which seems like it might be a path issue, but I’m using the full path. I even tried changing to the script dir first but that didn’t work. Something to do with busybox maybe?
Following your link it looks like some of the previous user’s issues were resolved by upgrading from 17.11 but we’re already using a newer legato than that (18.10.3).
So your system(“/tmp/test.sh”) call runs just like that? Nothing had to be added to the .adef?