Abnormal transmission P locking mechanism

I have a 2005 Prius. I came home from an 11 day vacation, and my car was completely dead. Locks/lights/everything. Next day a friend jumped it for >45 minutes and drove it around, working again fine. Later that evening when I went to pick it up, it was able to be unlocked with the fob, turned on with the fob placed, but locked the fob in the holder and would not completely start. Was able to turn it off again, but would not start or release the fob. After attempting to charge it again, the fob released. Approx, after charging for 15 minutes the car was able to be turned on, but the parking button was flashing, a large red triangle with ! Came on, and the screen said abnormal Transmissions P locking mechanism. I was unable to put car in park, or any other gear. I had my 12V battery checked about 3-4 months ago and it still had a good charge to it, not really sure where to start.