My Toyota Avalon won’t start after disconnecting the battery for a couple hours and then reconnecting. The hazard lights blink when I open the door now. Is it the anti theft system ?

I just read this post while trying to get my car to start. I thought I had tried everything and my next option was going to be replace the terminal connectors. Thank goodness for this post My car started right up after manually locking all the doors and following the rest of the instructions here Woohoo!!!! Thank you

G A, Thank you for your fix. Ihad to recharge my battery and couldnt get the horn to stop once i got charged up again. I had to drive the car to an empty lot away from my neighborhood scouring the net for answers. It was 95 degrees and i'm already sweating from adrenaline and i just charged the battery so can't run the AC. Your answer worked the first time and allowed me to go home. Thanks again!

So ... what was the solution?