http://pastebin.com/d2LK5Ypb

When I placed 5 encrusted obsidian blocks in a + shape and punched out the middle one in single player creative mode, the screen hung for half a second and minecraft crashed. This was during the night in that dimension (accessed by drinking a brew of sleeping).

I entered the world again, and the blocks were there without the rift in the middle. When they received a block update, I got the same kind of crash, so it seems to be reproducible. The report for that one is here: http://pastebin.com/YkGfmjsD

I opened up minecraft a third time, and this time the rift was there. I place blocks to create another rift and get a crash: http://pastebin.com/mLLnRN5E

I haven't tested water flowing through the rifts, or making the rifts in other dimensions apart from in the overworld where it worked without a hassle.

Interesting, thanks for the detailed report. Will look into it.

Thanks for the very prompt response :)

Ah, I think I know what's happening. The ender rift is using part of ender portal's functionality, and ender portals can only exist in the overworld, so the ender rift is setting itself back to air whenever it is placed by the encrusted obsidian.

Whoops! Thanks again for the bug report. 👍