If this happens often, you should copy the crash report and include it. Otherwise Mojang (or online mods) won't be able to know what problem you're having.
Depending on your resource pack, there may already be an updated version for snapshots. You could try and find out whether this is true for yours and keep playing with your resource pack on, including the 1.8 textures.
You're right Henry Verveer, it's working as intended.
This is intended in 1.8
Do you have a texture pack on? If so, try it on default. You're texture pack may not be updated for the new enchanting GUI.
Confirmed for snapshot 14w11b
It's indeed block 36, but in my case I want to have a block which you can't interact with and can't see, so the barrier can't be used for that unfortunately...
After restarting the game, it does work with any block but piston_extension.
It can be recreated by, among others, walking over soul sand.
Never mind