Cannot break any blocks without tools after changing gamemode / Adventure mode

I started a world on survival and started playing I made some awesome things and I had bonus chest: on and cheats: on. It was going pretty great until I used /gamemode and changed it to creative mode so I could make some sort of large structure. I switched back to survival and everything was fine for about one hour and then I could not break any blocks whatsoever. I tried using my hands to break all kinds of different blocks and they would not break it was as if I was hitting air. I tried hitting dirt with a shovel and to my surprise it broke. I did not find out what the cause was until I eventually made another world and then was able to pinpoint the problem. If you have an item or not item in your hand you can not break any blocks. I fixed it by putting all my inventory items in a chest on my broken world then I found my coordinates. after that I made another world and replaced the broken level.dat with my new ones and had to f3 and just search for my previous coordinates