Ok.
To MRDSBOY
And you can use PattView to get your patterns back.
See, on-topic XD
off-topic side-note: Page 15 is mine, too!!! >:) Muhahahahahahaha
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Use a backup save.
The only way I can think of creating a corrupt save is to edit a pattern that's not really in the game. Say you edit Player 4 pattern 1 when you don't have a player 4 in the game. It'll update a checksum without completely adding all of the pattern details. This can also happen when you add an NPC pattern when there isn't one there.