The diagnostic code that you are observing (Learn button flashing six times) indicates that the receiver logic board has detected a motor circuit failure through its self diagnostic circuitry. Internal schematics of the receiver logic board are not available to explain further details of this fault code. Since the motor and all of the functions (except the security light) are working properly, you could be getting a false fault code from the receiver logic board.
You may be able to clear this code by unplugging the unit to completely disconnect electrical power. Leave it unplugged for 3 to 4 minutes. When you plug it back in, the control board will reset. This may eliminate the fault code. If it reappears, you could have an internal problem in the receiver logic board. If everything is working normally, you should be able to continue to use the garage door opener even though it is flashing the fault code.
Regarding the failure of the light to turn on when the beam is interrupted, I recommend trying to restore this feature using the procedure on page 30 in your owner's manual. With the opener lights on, hold the light button for 10 seconds until the light goes off, then back on again. This tactic may restore your Security+ light feature.
If you need more help with these garage door opener problems, resubmit a question with additional details.