"Run Build" crashes due to a "Rendering Overlay" problem.

  Every time I "Run Build", the Mojang loading screen pops up, and just as the bar fills, the game crashes right before I can see the main menu. My workspace was just fine earlier, and the only things I modified before the issue occurred, were some block "Hardness" & "Resistance" values (reverting these changes seems to have no effect). The crash report can be found at the PasteBin link below, if anyone can please help. [Also, I've already tried deleting "<workspace dir>/src/main/java" and then regenerating the workspace code, but that also has no effect] :
"Rendering Overlay" Crash Error - Pastebin.com