Cause: The save file region mismatches your game. (e.g., You imported a European/PAL save into a USA/NTSC game folder). Fix: Check the Game ID. For PAL, the file name might be "SLES-12345" vs. USA "SLUS-12345". You cannot cross-region save without hex editing the encryption.
If you are comfortable with command lines, the true power of "mymc memory card" lies in its scripting capabilities. mymc memory card
In the early days of PS2 emulation, moving a save file from a PC to a friend's actual PS2 console was a nightmare. The PS2 memory card uses a specific cluster-based file system that is not natively readable by Windows, macOS, or Linux. Cause: The save file region mismatches your game
If you simply copied the .ps2 file to a USB drive, a real PS2 console would not recognize it. mymc solved this by allowing users to "unzip" the game save from the image into a standalone file format (like .psu), which could then be transferred to a physical PS2 using homebrew tools like uLaunchELF. For PAL, the file name might be "SLES-12345" vs
You might wonder, "Doesn't PCSX2 have a built-in memory card manager?" The answer is yes—but it is limited.
PCSX2’s native browser lets you delete files and view icons, but it does not let you inject external saves or export raw .psu files for use with real PS2 hardware via a USB drive (using tools like uLaunchELF). This is where mymc memory card becomes irreplaceable.