Fixing "it appears that this was not the last save game"

Quaint solutions to unusual problems

Introduction

So you've been playing Unexplored, and the game might have pooped itself just a little, and now you can't load your save file because it says "Something went wrong, save game could not load. For some reason it appears that this was not the last save game":
As it usually goes with these things and human luck, it was probably your best run to date, and you have put no less than a few hours into this save file already, thus giving a bitter aftertaste to the whole situation.

But, not to worry, with a few minutes of work, it is possible to convince the game to disregard this specific error and let you continue your adventures.

Setup

For this guide you'll need two pieces of software

• ILSpy, a program for exploring the general logic of executable files in specific format (which Unexplored also uses)
  Download ILSpy_binaries_3.2.x.zip from GitHub[github.com] and extract that archive somewhere.
  (newest supported ILSpy version is indicated on Reflexil page and is currently 3.x)
  
• Reflexil, a program for making small changes to executable files in that same format
  Download reflexil.for.ILSpy.<latest version>.bin.zip from GitHub[github.com] and extract it to the same directory as ILSpy.

If all is well, upon opening ILSpy there should be a gear-shaped button for Reflexil on the toolbar:

Instructions

First, make sure that the game is not running. Kind of obvious if you are going to do anything with game files, but - just in case.

Right-click Unexplored in Steam library, pick Local Files > Browse Local Files


Make a backup of your Unexplored executable (the one that has the game's icon and all), just in case anything goes wrong.

Now, open ILSpy and either pick your Unexplored executable (after picking File>Open), or just drag-and-drop it onto the ILSpy window:

Once that is done, ILSpy window's left pane should show something like "Unexplored (0.0.0.0)":

Click [+] on the left of that to expand it, then expand "Unexplored.Core", then expand "GameManager", and finally click "LoadGame(string):int" inside of that. A volume of code appears on the right side:

This might look intimidating, but, don't worry - you don't need to make sense of most of this. What you do need is to press Ctrl+F, enter "return -3", and see what's the text on the line of code before that (highlighted for clarity here):

Now, click Reflexil's "gear" button on the toolbar (shown in Setup). A panel appears on the bottom.
Here, you want to make it bigger, and find a line that says "ldstr" and then the text of error as you have seen it in the code:
As of writing this guide, it's at line 273 (offset 882), so that's a bit of scrolling to get there.

Then, you want to locate two lines a little below, saying "ldc.i4.s -3" and "ret" accordingly, right-click them, and pick "Replace with NOP":

After you've done so, the view should look like this:

Now, you can scroll down a little further, find another pair of lines saying the same, and replace them with NOP too.
Most likely you wouldn't need this, as it detects a more uncommon condition, but I'll mention this here just in case.
As of writing the guide, these are at lines 338/339 and offsets 1065/1067:

Finally, you scroll the left pane all the way back up to Unexplored, right click it, pick Save As, and replace your Unexplored executable with the new version.

If everything was done correctly, you can now run the game again, try to load your save file, and, lo and behold - the game is now happy to do so, and hopefully nothing else is broken

If this is a singular occurrence for you (for me it took about 200 hours of playtime before running into this issue for the first time), you can now press "Save & Quit", close the game, and replace the executable with the backup copy that you made earlier.
If this happens more often, you would keep your modified executable - just mind that you'd have to redo these steps when an update happens

Have fun!

[Stop the Insanity]

Hey man, this is probably an old guide now but I just wanted to say thanks a lot for this. I had to download a few different versions of ILSpy and Reflexil before I got 2 that were compatible for some reason, but after that it was smooth sailing, and my game loaded!

I don't know much about code, but based on the "Save scum check failed" note in the code, am I to assume the programmer coded in some sort of attempt at a save scum deterrent that actually just legitimately corrupts save files willy nilly? That's messed up. Trying to control how someone who buys your game plays it is already messed up, but when you're so devoted to it that you allow it to break your game for years is even worse.

That's too bad, because if it wasn't for this horrendous save file corruption that seems to happen to me on any run I start to get 8 - 10 floors deep on this would be one of my favourite games.