Hey there! I have noticed a "regression" of sorts in using mx4sio with OPL BDM and/or daily github builds. I have a couple of russian double-language pirate PS2 discs that I have made iso dumps of and copied said dumps to a microsd that I use in mx4sio, they use game loaders that are essentially modified official PAL PS2 demo-disc menus to load two copies of the game, one translated and one original. Recently, I decided that it'd be a good idea to upgrade my OPL install to the latest version (spoiler alert: it was not a good idea), so I tried three different OPL versions: the official one from github (v1.2.0-Beta-1979-d26da79), BDM 4.7.1 version posted not too long ago in this same thread and another one of the BDM test builds, BDM_CC_TEST_V2. All of them didn't work, instead of launching into the demo menu, they just load to white screen, although, with one of the older builds, can't say which one specifically (because I overwrote that one "good" version that was on my memcard with the newer one), but I have some older OPL builds left on my PC for me to test. Once I test them, I'll come back with results.
Also, my ps2 model is 75k slim and I'm using a custom-ordered self-assembled mx4sio PCBs
If you did, which version did you end up backing up to?
