NOT FOR USER MISTAKES OR TROUBLESHOOTING HELP.
Questions about legality? Post in the Pokémon Legality sub-forum instead.
Please share:
1. How you caught the mon:
Location: Is it event/wild area event/wandering/in grass/den etc
Level: Level it was met at, and perhaps how many badges you had then etc. All Changes: Have you changed the moves, have you since evolved it, has it been trained, did you change the PID or IVs or Height or Weight or EC, etc.
2. Upload actual file PK to your post (our forums support direct uploading).
3. Version of PKHeX you're using.
All 3 needed. They're a must!
Thanks.