Posted By: bandit
Downgrading your PS3 MAY in SOME cases STOP you from watching any Blu-Ray movies! (Games still work!)
Quote by garyopa
Ok, we need to work on this Blu-Ray playback it is MAJOR PROBLEM!
I was able to restore one machine I had, by copying over all the files I had in the /dev_flash2 and /dev_flash3 back to the HDD, that I had saved before when it was on v3.41
But that does not help those that were on v3.50 factory fresh or with no previous full /dev_flash2 & 3 backup.
I not sure what file was that fixed the problem.
We need more machines, more tests.
I going start a thread and warn people right now!
Reply by Mathieulh
Source: @Mathieulh (via) TwitLonger
The people having bluray movies playback issues after downgrading, this happens because you updated to a modified PUP (psjb one) which has its /dev_flash3/ tarball swapped (probably to a debug one, debug consoles do not sport bd movies playback) with other CRL/DRL revocation files.
Having read some posts online, it seems that majority of people who did downgrade, still have a working BD Playback for movies. Interesting. Could it be the downgrade files (modified 3.41 PUP) that is causing the problem?
*UPDATE to possible fix by Mathieulh*
Replacing /dev_flash3/ to a backup according to multiple accounts, fixed the problem.
However, the above method does no good for consoles that came pre-installed with 3.50 as there is no "dev_flash3" to backup from. You can also see what other people are using to downgrade, what consoles they're using and if they are affected over at PSX-Scene (Blu-ray player, does yours still work after downgrade).
Image via comments