Urgent Help Please!

[NOOBMaster]

This morning, i ws editing the game data. Then i saved and shut down the PC. This evening, i opened the file and i keeps o saying "unexpected file format". Can someone pls help me?

[Dalton]

Are you using RPG Maker XP?  If so and you're trying to open it with Postality Knights, open it with the legal version, if you're trying to open it with the legal version, open it with Postality Knights.