Have you try the new game “Tekken 6” with Custom Firmware 5.50 GEN-D2 on your PSP yet? If yes, so you know this was not going to work because it required the new firmware 6.10 or 6.20 to read this game. In additional, the Yoshihiro’s decryptorV4 could not decrypt Tekken 6 either. It gave us this message “Error: 0xd9161f0 unknown tag”.
The latest two games were released Phantasy Star Portable 2 japanese DEMO and Tekken 6, which required higher firmware 6.10 to read. We were compared these two games to the older one in application UMGEN v4.00, and we found out there is an extra file contained inside the UMD “OPNSSMP.BIN”.
Good News is that Yoshihiro developer replied on PSPGen forum about this issue and he will be release a application or Yoshihiro decryptor V5 soon to solve it, no released date given.
Source : http://www.pspgweber.com/psp-article...Decrypter.html