Update to say that I reinstalled Windows RedStone 4 (fresh Windows, but didn't format the drive). The issue still persisted - so it wasn't the Red Stone update to blame.
I then ended up nuking n' paving (formatted and reinstalled Win 10 RedStone 4). NOW a simple 'click the start button' script works again. This was all with the SNAPSHOT 2019-03-20 build.
So, some wires where seriously crossed and I still have no idea how to uncross them without this 'last resort' solution. I still have no idea how thy got crossed in the first place - Sikuli worked on this machine and then when I tried it again a few months later, it didn't work.
Update to say that I reinstalled Windows RedStone 4 (fresh Windows, but didn't format the drive). The issue still persisted - so it wasn't the Red Stone update to blame.
I then ended up nuking n' paving (formatted and reinstalled Win 10 RedStone 4). NOW a simple 'click the start button' script works again. This was all with the SNAPSHOT 2019-03-20 build.
So, some wires where seriously crossed and I still have no idea how to uncross them without this 'last resort' solution. I still have no idea how thy got crossed in the first place - Sikuli worked on this machine and then when I tried it again a few months later, it didn't work.