Whilst starting a new game on this scenario I get the following error message:

Error while running event level::on_player_created (ID 26)
Unknown entity name: factory-input-combinator
stack traceback:
[C]: in function 'create_entity'
...ng/Factorio/temp/currently-playing/scripts/factories.lua:93: in function 'handler'
core/lualib/event_handler.lua:47: in function <core/lualib/event_handler.lua:45>

Other mods running outside of the dependency are Disco Science (https://mods.factorio.com/mod/DiscoScience) and long inserters (https://mods.factorio.com/mod/Long%20Inserters), but testing with only dependencies gives the same error. Does anyone know how I might fix this? Would really like to play this scenario.

I just ran through both, and also in the one where I added a bunch more mods

I dont get that error, I run it through game version 1.88 and it runs fine - atleast just when I ran through and checked

What versions of which mods are you running with? Running on Factorio .87 with all mods on latest versions (both just deps and your mods), but it doesn't throw any errors for me. The factory input combinator is an entity that has been added by my mod since the start basically, so it seems weird that it would break all of the sudden.

Also, didn't expect to come back to my Factorio mod by checking a YouTube comment section :P

This seems to occur because you are attempting to start it as a scenario - I missed that in your original issue. Please don't load this mod as a scenario, as it is a fully functioning mod. Install it from the integrated mod browser.