Look in events.log and verify that BasementSensor is indeed changing when the motion is detected. The log statement is saying that it is updating the state which may not result in a change in the Item’s state in which case the rule will not fire.
See this for some similar code that works. One thing I notice with this rule, assuming that it was working, is that the light will turn off in 30 seconds no matter whether the motion sensor continues to report motion.
Did you see switchtest.rules loading in the logs?
Do you see SwitchC1 changing in events.log?