Corrupted HG save file from a cartridge, I can't even load it via the latest version of PKHeX.

[Matticus3007]

As the title says, my save file from a physical cartridge is seemingly corrupted. I can't even load it via the latest version of PKHeX. When I start the save on the game the screen just stays black, no message says the file is corrupt or anything. I managed to get the save working by starting a new game, then resetting the game once you gain control of your character with L+R+Select+Start and selecting my old save. But turning off my 3DS then causes the same problem the next time I start the game. I saw a reddit post where something similar happened to someone who saved at the Burned Tower, by resetting I found I had saved at the Lake of Rage. Someone else replied on that same post saying they had saved at the Lake of Rage too and this had happened.

I have not edited the save in any way, this has been a clean playthrough. I only recently installed stuff like Checkpoint on my 3DS, and this happened before it was installed. I've included the save I extracted via Checkpoint below. As far as I know, the cart isn't legit but has worked fine up until this happened.

Is there any way I can rescue the save?

POKEMON HG.savFetching info...

[Kaphotics]

Open it in a hex editor and it's obvious it's not a Gen4 save file.

[Matticus3007]

Weird, those are some of the other roms I have installed on my 3DS. Once I managed to open the save file by resetting after starting a new game I moved away from the lake of rage and saved again to see if that did anything, could that be why the save file is like that?