Stack trace when mined:
Error while running event crafting_combinator::on_pre_player_mined_item (ID 11)
crafting_combinator/script/util.lua:86: attempt to compare number with nil
stack traceback:
crafting_combinator/script/util.lua:86: in function 'rotate'
crafting_combinator/script/cc.lua:452: in function 'find_chest'
crafting_combinator/script/cc.lua:176: in function 'update_chests'
crafting_combinator/script/cc.lua:150: in function 'destroy'
crafting_combinator/control.lua:91: in function <crafting_combinator/control.lua:88>

There are combinators saying there is no space in their. Added correct chest location in the UI to no avail. When I mine the complaining ones I get that crash.

Also of note, there are pairs of crafting combinators sharing overflow chests (back to back) as well as combinators reading the recipe from the factory
Bob's Mod is installed and I'm using this to switch between crafting gears on all stations and crafting Balls + Ball-Bearings on alternating stations. Let me know what else might be useful

Ah, Also getting it when mining the chest behind it

Error while running event crafting_combinator::on_pre_player_mined_item (ID 11)
crafting_combinator/script/util.lua:86: attempt to compare number with nil
stack traceback:
crafting_combinator/script/util.lua:86: in function 'rotate'
crafting_combinator/script/cc.lua:452: in function 'find_chest'
crafting_combinator/script/cc.lua:176: in function 'update_chests'
crafting_combinator/control.lua:96: in function <crafting_combinator/control.lua:88>

Here is a minimal reproduction of the error: https://pastebin.com/mM5GtRHN

I found an in-game fix and have a suggestion
In game ALL the combinators need to be set to have a valid chest-position. Even ones that are only reading.

If a default is given to combinators that don't have a valid chest position attribute it should be fine (or add nil checks, but whatever works)

The defaults should be filled out properly for the added settings in 0.13.3. Hopefully that fixes your other issues as well :P

Thank you for getting to this so rapidly
I'm afraid it actually prevents loading of my map:
Error while applying migration: Crafting Combinator: 0.13.3.lua

crafting_combinator/migrations/0.13.3.lua:8: attempt to call method 'fill_defaults' (a nil value)
stack traceback:
crafting_combinator/migrations/0.13.3.lua:8: in main chunk

I think I saw another thread reporting the error as well