This is an unusual scenario, but the error message does say "please report this error". If I have a blueprint that contains only tiles (no entities), and use that to click on the Landfill Everything button, I get the following error:
The mod Landfill Everything caused a non-recoverable error.
Please report this error to the mod author.
Error while running event LandfillEverything::on_gui_click (ID 1)
LandfillEverything/control.lua:40: attempt to get length of local 'entities' (a nil value)
stack traceback:
LandfillEverything/control.lua:40: in function 'add_landfill'
LandfillEverything/control.lua:176: in function <LandfillEverything/control.lua:168>
I was thinking I might be able to use concrete to layout the planned shape for a chunk of landfill. I was also hoping I could use concrete to indicate areas of my nuclear blueprint where I don't want holes in the landfill. (This doesn't do what I hoped. My alternative approach is to put lamps in all the gaps.)
Thank you for this mod. I've found it very handy for building nuclear reactors, and also useful for allowing rail intersections or arbitrary factory builds to overlap the edges of inconvenient lakes.
If I can tack on a feature request: It would be nice if this mod could have an optional dependency on the Platforms mod, and allow adding platforms to a blueprint instead of landfill.