I have downgraded my psp from 5-50 gen d2 to 5-00 m33-6.Then i copied a few games into my memory stick.When i select a game,i get the error code 80020148.

Then i saw some of the solutions already posted in this forum which are as below:
-Unsupported PRX type | This error also seems to appear when you are running an iso with a fake mem.
-Upgrade to a newer custom firmware, or u are using official firmware and u need to downgrade then install CF.
-If not, it is probably a config error/bug and 99% of the time it will be fixed if u "delete flash1 and reset settings" in Recovery>Advanced.
-Often occurs when upgrading from a older OE/SE to M33.
-can also be bad/corrupt iso
-can be from not having 1.5 addon installed when running some homebrew(fat only)
-can be fake memcard.
-also occurs with older SE/OE firmware if u have umd mode set to M33 driver(fixed by changing to sonynp9660 or put in a umd)
-also can be fixed by upgrading to 3.52M33 from older CF
So,i formatted"flash1 and reset settings" in Recovery>Advanced

Then,i get the error 80020321
-I changed iso loader(in recovery or vsh menu) to SONY NP9660 as mentioned in the link
http://forums.dashhacks.com/f127/psp...-mean-t229694/
Then,i get the error 80020148 again!
Please help.