The mod Abandoned Ruins - Updated (1.3.14) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event AbandonedRuins_updated_fork::on_chunk_generated (ID 15)
AbandonedRuins_updated_fork/lua/spawning.lua:407: attempt to index field 'spawn_chanes' (a nil value)
stack traceback:
AbandonedRuins_updated_fork/lua/spawning.lua:407: in function 'get_spawn_chance'
AbandonedRuins_updated_fork/control.lua:159: in function <AbandonedRuins_updated_fork/control.lua:136>

Crash

Same error here, looks like maybe you (the dev, I mean) might've misspelled the variable name for spawning.spawn_chances on line 407 in spawning.lua? It returns with it spelled "spawning.spawn_chances" at the end of that function but it's missing the second "c" in "chances" earlier up in the elseif condition.

Yep, just relaunched it with that line edited and I'm not getting the error on startup anymore :)

To fix the issue until it is updated.
%appdata%\Factorio\mods
Open the mod zip. Look into folder "lua" and edit "spawning.lua" look for "chanes" replace with "chances"
Save and reload game.

Ops! Tpzo found. Thank you. :-)

1.3.15 should fix all those typos. Hmm, LUA isn't doing any lint-checks at loading the script. That's very tragic as it let slip more mistakes like this through.