Legality check false positives (I think)

[Shady Guy Jose]

Way back when, I used the Poké Transporter .exe tool to move a bunch of Pokémon from Heart Gold to Black (JPN). Most are fine, but some are now throwing legality errors on PKHeX. Some may be corrupted, but others shouldn't be flagged. Take the attached Skuntank, for example (taken from a Black save). It says Night Slash is illegal, and I'm guessing it's because it would only learn the move later in B/W. However, in Gen 4, it's learned at level 31/32, so it's perfectly legal. I have several of these cases in this file. Should I attach them all, or is it enough to implement a previous gen level-up check? Also, the event dogs/Celebi are throwing a PID-Nature mismatch that shouldn't be happening either, I think. Can anyone give me an insight as to what's happening here? Last but not least: some moves are giving me PP errors (Petal Dance is a frequent offender). I'm guessing the max PP got changed from one gen to another and the aforementioned tool didn't catch this. What should I do in this case? Manually fix the PP and that's it?

EDIT: This unrelated .pk4 Eevee says it shouldn't have been hatched at this location. I'm positive I've never tampered with it.

EDIT2: I found the original Heart Gold save file and moved Skuntank again with PKHeX. It's now legal, despite still having Night Slash. I'm even more confused now.

EDIT3: Found the errors for the dogs. The Natures had been corrupted by the old program, I found the correct ones, set them back, and they're now legal. Deleted those attachments for convenience.

EDIT4: Legit (in-game, never modified) Cloyster throwing an error — missing ribbons

435 - スカタンク - 5DDFC8E39B03.pk5

133 - EEVEE - AC8D4DFFE240.pk4

091 - Cloyster - 736CF36DFFA6.pk6

Edited February 12, 2020 by Shady Guy Jose