Adding the exact line gives me the error that the path doesn't exist. So I changed it to ~/Data/Temp where I keep my files.

I see I need to set read/write permissions, is this a new thing in the latest editor? Or shouldn't I need to set permissions?

By the way, the C:\Windows\TEMP error occurs only the first time the page is loaded. If I refresh after the error it's ok, so I think it's unnecesary to manually create a temp path and set permissions on it?