Ribbon world maps with ores against the void will cause a crash as the planner attempts to place items in the void

"2239.893 Error MainLoop.cpp:1432: Exception at tick 72954: The mod Mining Patch Planner (1.6.26) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event mining-patch-planner::on_tick (ID 0)
mining-patch-planner/layouts/simple.lua:1329: attempt to index field 'default_cover_tile' (a nil value)
stack traceback:
mining-patch-planner/layouts/simple.lua:1329: in function <mining-patch-planner/layouts/simple.lua:1276>
(...tail calls...)
mining-patch-planner/control.lua:45: in function <mining-patch-planner/control.lua:32>
"

Thank you for the report, released an update that fixes the crashing. I know it doesn't really properly avoid placement on void but try using the "Avoid water option", it will at least not place mining drills out of bounds.
Edit:
Needs Factorio version 2.0.18 (currently experimental) at least because of another feature.