I'm using PasteInto in a script and find that paste external to photoshop on win10 doesn't work when running the script.
Can you elaborate on that? I do not understand what you mean. What are you actually doing and what do you expect to happen but does not happen or works incorrectly. Posting the script that does not work would be helpful as would the version of Photoshop your using. I using Windows 10 preview have CS2, CS6, CC, CC 2014, CC 2015, CC 2015.5 and CC 2017 installed and could test your script to see what happens on my machine.