Sorry if I posted this in the wrong section but I had this problem and have seen many complaints about this on the internet without a fix. Thought I would share my solution:
The "permission problem" exists if you are using the "HP Scan" program, But if you download the "HP Smart" app from the Apple app store and use that, the scan works again. Then delete the "HP scan" app
The "permission problem" exists if you are using the "HP Scan" program, But if you download the "HP Smart" app from the Apple app store and use that, the scan works again. Then delete the "HP scan" app