I just decided to load up Minecraft after probably a 3 year or longer break from the game. I started up my main map with all my creations and to my surprise after the map finished converting, lots of grassblocks were missing and was sort of just removed from the map.
Now last time I played was back in the 1.0 days, so I tried it out with version 1.0(of course, using the unconverted map) and it seems to be working all fine.
Why is this happening and how can I fix it? I am fairly sure it has something to do with the world conversion. I did convert this world to a new world format in the past but that was around 1.0. I believe there was another new world format released after that sometime during my break.