That is not a save file.
Did you use Checkpoint to get that? Checkpoint is broken for NDS games, use TWLSaveTool instead: https://github.com/TuxSH/TWLSaveTool/releases/latest
You are supposed to open save files that are created when you save ingame, as you would do on your console. Save states created through the emulator menu are not supported.
Why would you want that? It's not recommended to use outdated versions.
If it's for ALM, get the latest version, which is compatible with the latest PKHeX, from santacrab2's fork: https://github.com/santacrab2/PKHeX-Plugins/releases/tag/25.02.23
I think what they meant is that at some point during the last two weeks somehow over 200 saves and PKM files went missing.
2025/02/03: https://web.archive.org/web/20250203120729/https://projectpokemon.org/home/files/
2025/02/20: https://web.archive.org/web/20250220064410/https://projectpokemon.org/home/files/
No. The Ranger series is not supported.
PKHeX is made for the core series games and a few Spin-Offs that can exchange Pokemon with them (like RS Box and Battle Revolution).
In the Misc Editor you can edit records, but you need to know the Record ID for "Number of Link Trades". I'm not sure if anyone ever documented that.
The transfer from Gen 4 to 5 isn't a link trade though. It's only considered a link trade when it stays in the same generation.
Retroarch added 8192 empty bytes (FF) to the end of the file. You can use a hex editor to remove them, you might have to add them back to correctly import the file back to Retroarch.
Pokemon - LeafGreen Version (USA).srm
Nobody can help you with that. Downloading ISO files of a game is piracy, which is illegal and against the forum rules (which you should have read).
https://projectpokemon.org/home/guidelines/
The proper way to get an ISO is to dump it from the game you own with your GameCube/Wii. You can google for tutorials.
I wasn't sure how gen 1/2 handles the removal of a Pokemon after a trade. In Gen 3 they just remove the species ID but leave the rest of the data, I hoped something similar for gen 1/2.
So I opened your save in a hex editor and searched for the nickname. I found it still in slot 6 of the party, but the counter was at 5. After setting it to 6 I was able to see your Charizard in PKHeX.
There's another way. Poke J's PKX Extractor scans the full file for any Pokemon data. With this you could find your Charizard as well. However for gen 1/2 the OT and nickname need to be manually fixed.
Your Charizard is still in the save. When you traded it away it wasn't wiped from your save. The party counter was set to 5 so the 6th slot wouldn't be read any more, but the data was still there.
0006 - CHARIZARD - 47A4.pk1
You can add a spoiler and move your images inside.
Or create a gallery album to upload your images and provide a link to it https://projectpokemon.org/home/gallery/
PKHeX 24.11.11 is still for NET8 and is incompatible with WC3 Plugin 2.3.0. You have to use 2.2.2 which is also still for NET8: WC3Plugin-2.2.2.zip
For 2.3.0 you need to get the latest development build of PKHeX, or wait for the next stable release.
You can't really differentiate between them. PKHeX does this by checking the file name. VC saves are usually called sav.dat (any other name would not be able to be imported back into the VC).