Failed to load mods: space-exploration-productivity/data-final-fixes.lua:69: attempt to index field '?' (a nil value)
stack traceback:
space-exploration-productivity/data-final-fixes.loa:69: in main chunk

Hello!
Could you plase either share the versions of both the space exploration mod and this mod; or enable the mod, launch the game and after the crash, share factorio-current.log, located at C:\Users\<USER>\AppData\Roaming\Factorio? This would greatly help me solve the issue!

This problem could occur if you are using an old version of space exploration which does not support spaceship landing.

You can also manually download version 0.3.0 of this mod, it shouldn't have this problem.

Let me give you both so you have everything to work with:

Full: http://kacey.0x.no/factorio-current.log
Relevant:
$ cat factorio-current.log | grep -i "productivity"

1.146 Loading mod settings space-exploration-productivity 0.3.1 (settings.lua)
["space-exploration-productivity"] = "0.3.1",
25.905 Loading mod space-exploration-productivity 0.3.1 (data-final-fixes.lua)
25.906 Error ModManager.cpp:1574: Failed to load mod "space-exploration-productivity": space-exploration-productivity/data-final-fixes.lua:69: attempt to index field '?' (a nil value)
space-exploration-productivity/data-final-fixes.lua:69: in main chunk

Versions:
Porductivity for Space Exploration: 0.3.1
Space Exploration: 0.5.67

After an unrelated to this mod nightmare of Steam not launching Factorio, I finally got the 3.0 version set and it does seem to work just fine.

Ended up having to download the game from Factorio and install it over the Steam installation (in steamapps folder). Some reason Steam just refused to launch the game at all. Integrity check had no issues. reinstall of the game through Steam didn't help, nor reinstalling Steam itself.

I have both bad and good news for you- good is that I managed to fix the issue. It was with the seoh mod, which removed some of the entities.
The bad news is that you had to do all this nightmare work for nothing. Sorry!

I will release the fix in a couple of minutes.

Awesome, glad to hear you were able to get it fixed, I really appreciate it!

And the issue just came up out of nowhere. I'm kinda puzzled to what happened, it was the game arbitrarily became incapable of launching. Nothing changed between exiting and relaunching the game. I even restored all the configs I backed up after wiping the game from trying to reinstall via steam and it had no problem with those configs after installing the game with the downloaded installer over the Steam version. I couldn't find much from a google search about Steam not launching it. It just sat there saying "launching game" or "preparing to launch" but factorio.exe would never pop up in task manager. Just Steam being a derp.

Released the fix.
Just as a warning: while trying to fix the mod, I discovered that seoh (simplified SE) not only removes some of the entities, but also makes spaceship landing (the one that you build yourself) completely useless, because none of the factories now work on a landed spaceship (they just don't have any recipes in them for some reason)

Just as a warning: while trying to fix the mod, I discovered that seoh (simplified SE) not only removes some of the entities, but also makes spaceship landing (the one that you build yourself) completely useless, because none of the factories now work on a landed spaceship (they just don't have any recipes in them for some reason)

Good to know. Ultimately that sucks, but I haven't reached that point in the game quite yet.