Strange death in the nether!

[Shifty3000]

So I keep getting insta killed in the nether and I'm not sure why, i get a message about dupe but all I am doing is flying around or killing mobs.

upon breaking my grave I receive all my items back except my [/dev/null] is that the item that is causing the issue? 

Kinda worried to go to the nether now in case i insta die over lava.

[brunyman]

do you have the coordinates where that happens or the location does not matter?

[Shifty3000]

It's happened 3 times all in different locations. I'll try and re-create it later and see whats in the console.