Cannot authorize user to edit apps-script

Question

I wrote an apps-script attached to a Google spreadsheet, then transferred the ownership of the spreadsheet to another user. However, the new user cannot edit the apps-script and is not authorized to run it. I read that Google has upgraded permissions to have apps-scripts inherit the permissions of their parent spreadsheets, but that doesn't seem to be the case.

Answer 1

The permissions was upgraded, but in an opt-in way. If you open the script and click the "Share" button it will ask you to upgrade to the new permission model.