I'm running FML: MCP v9.05 FML v7.10.18.1180 Minecraft Forge 10.13.0.1180 with all three Mek mods on 7.0.0.59. There aren't any crash reports or Forge logs generated when the following issue happens.

Steps to reproduce:

• While in creative mode pull out an Electric Pump.
• Place the Electric Pump in the world
• Client is abruptly ejected from the world, given a "Connection was terminated" message, and returned to the multiplayer server select screen (note: I was playing single player at the time)

Another user on the Minecraft Forum post for Mek reported the same issue when placing a Digital Miner in the world.

Experienced this with the fluid pipes. Seems to be related to WAILA and retrieving NBT tag data. I think WAILA needs an update for this issue to go away.

I agree with deanorhan on the root cause. I created a new instance of my modpack in MultiMC but removed WAILA (and realized I was using 1.5.2.a as I did so) and the issue went away.

No issue here: http://puu.sh/a8Vov/7db83bf014.png