(Solved)[0.17.79] [non-modded] Critical error on startup (Base mod: 'circuit_connector_definitions' nil), Windows 7

[Gust]

Cannot launch the game.

An error "Loading mods" on startup:
Failed to load mod "base": __base__/data.lua:5: __base__/prototypes/entity/demo-entities.lua:1224: attempt to index global 'circuit_connector_definitions' (a nil value)
As you cannot disable Base mod, the only option is to Exit.

Solution that worked for me:
Completely delete Base folder and reload it from Steam via Verify integrity of game files.

Empty install on older laptop with Windows 7 (wanted to play Factorio during long vacation =). Already tried to reinstall and validate cache - no change.
I even updated video drivers...

Update: Rolling back to latest 0.16 version gives the same error.

P.S. In 2017 this machine handled Factorio very well.

[posila]

Can you open folder where Factorio is installed (for example right-click Factorio in Steam Libary, select Manage -> Browse Local files) and do file search for a file named circuit-connector-sprites.lua? How many files does it find?

[Gust]

Can you open folder where Factorio is installed (for example right-click Factorio in Steam Libary, select Manage -> Browse Local files) and do file search for a file named circuit-connector-sprites.lua? How many files does it find?

Actually, Search found 2 files. New one in Core folder and another one from 2016 in Base folder. I completely deleted Base folder and then reloaded it back from Steam ("check integrity of game files"), and it fixed the problem!

Seems like complete reinstall (Steam - Uninstall) was not removing these old files.
Just FYI, invalid file was from 27.06.2016.

Thanks.