A player on my server had this issue when using a bucket - http://pastebin.com/C8cng4nj

From the player:
"All that happened was that I had a stack of 8 buckets and was flying with Wings of the Bat over the river in the base. I started clicking to see if I would hit a source block, and crashed at one point. No source blocks seemed to be in the area I was clicking."

The river in our base is a stream from the Streams mod which uses nonstandard water blocks.

Alright thank you, I'll investigate this

Awesome, thank you for the prompt fix!

Thank you for telling me, could you explain the steps needed to reproduce the crash?

It's a pleasure :)
Please do not hesitate to tell us through issues if you encounter more problems