Thanks Jan for the hint to the new driver. This helped and brought the "scan" button back into the printer menu. But still the scanner driver "Samsung Scan.app" could not be verified. So it did not open ....
I was able to cure this by disabling the Mac gatekeeper, run the scanner once successfully and then re-enable the Mac gatekeeper again.
To disable the gatekeeper:
- Open terminal from spotlight
- Type in the following command: sudo spctl --master-disable
- Enter your password
To enable the gate keeper:
- Open terminal from spotlight
- Type in the following command: sudo spctl --master-enable
- Enter your password