This may help someone. At our library we run minecraftedu on several computers for the kids. This week 3 machines would crash minecraftedu at launch. I did some diagnostics and found the issue. On the 3 machines the mod: computercraftedu (1.74) was added but not computercraft (1.74). Once I added computercraft (1.74) mod to the non launching machines minecraftedu worked normally. Took a while to figure out the issue.