Quote from MRDNRA
Just installed the latest version having not played for a while, and the default seed texture has disappeared (it doesn't even say "missing texture", the only way they can be seed on the ground is from shadows they normally create.)
Edit: Same with sticks, and couldn't craft tools as a result.
Edit 2: Updated forge from build 684 to 737 and optifine from D2 to D5, still same problem.
Forge 738 and Optifine D5 fixed it for me.