Action Replay DSI - Restoring Save Won't Work

[RSDJ]

I'm trying to use my modified Platinum save from PKHeX to overwrite my current save. However, when I try do this, it says:

Selected SAVE not compatible with currently inserted Game (wrong size).

What does this mean exactly?  The file type was the same when I exported it from Action Replay. Is my file name too long?

Edit: So unfortunately, I found out that it may be infeasible. The exported save from Action Replay works just fine with PKHeX, but exporting from PKHeX makes the file unreadable on Action Replay.

Edited May 31, 2022 by RSDJ
Found out that PKHeX doesn't support Action Replay formats.