PlayStation memory cards were formatted for specific regions (NTSC-U for USA, NTSC-J for Japan, PAL for Europe). A save file created on an NTSC-U (American) BIOS will often fail to load if your ePSXe is running a PAL (European) BIOS or ROM.
Unlock Everything: The Ultimate Guide to Tekken 3 Save File for ePSXe i--- Tekken 3 Save File Epsxe