I have read the previous threads regarding Error 45 and will check this evening to see if I failed to connect the GPS, I am pretty sure that I did but may not have fully seated the connector. So on Friday I was flying my Phantom 3 pro over the ocean, at the low battery alarm the quad to return to home. During the flight I had moved from the launch site so thought to change the home position to RC. The glare was such that I couldn't see the screen (I use and iPhone 6 +) despite the use of an antiglare screen protector and a sunshade. I am guessing that when trying to change the home position I inadvertently turned off the return to home as the quad started to hover. while trying to get back to the beach the critical battery alarm sounded and the quad started to descend that is when panic mode set in , when tried to climb I can't have pushed the stick straight up which of course changed the heading , I tried to correct but was desperately trying to climb. The battery gave out and the my quad fell into the ocean. I managed to recover the quad and immediately removed the battery then flushed it with fresh water, let it dry in the sun and then placed in a bag of rice. Yesterday I stripped it down and cleaned the circuit boards and motors with a non residue contact cleaner. I reassembled powered on the it powered up okay the app showed safe to fly non GPS. As I was in the house that wasn't too surprising. When trying to start the motors (without props) I received the Error45 message. My initial search online suggested it maybe a VPS error I checked all connections they look ok however I did see a pushbutton the VPS board and wonder if I may have pressed it while stripping down cleaning and reassembling. Now that I have read the threads indicating it is more likely to be the GPS I will check the connection, The GPS unit in the top shell was the only thing that I may not have cleaned correctly As I didn't remove the foam over completely. Any one know what the pushbutton in the VPS unit is for?