Upgrading to Retropie 4.4 makes old lr-fceumm SaveStates incompatible

[xadox]

I am using RetroPie on an x86_64 PC with Ubuntu 16.04.
After upgrading from 4.3 to 4.4 my existing lr-fceumm SaveStates become incompatible and do not load anymore. New created SaveStates are working fine.

Is there a way to revert lr-fceumm to an older build?

Edit:
Hmm... since I have a full backup of my 4.3 installation, I could try to replace just the fceumm_libretro.so file.

[tpo03]

@xadox I am having the same exact issue, however, I am running Retropie 4.4 on a Raspberry Pi 3 B with Raspbian Jessie. I can see the save states created from my gaming sessions using Retropie 4.3, but they will not load. New save states can be created and loaded properly. Other old save states for other emulators, such as lr-snes9x2010, work perfectly fine. It appears that there may be some type of incompatibility bug that occurs with certain emulators. @xadox Were you able to test reverting the nes emulator in question to a previous version? Until this issue is acknowledged and rectified, I’m reverting back to my 4.3 based image.

For reference: I personally installed an official Raspbian Jessie image and installed Retropie on top of that. I have not done any unusual modifications.

[matchaman]

Same issue on a fresh 4.4 image with latest updates on my 3B+ model. I don't have old .so files anymore so I can't check right now (I'd have to install 4.3 and copy from there).

[mitu]

I see lr-fceumm had some save states changes recently (see for instance https://github.com/libretro/libretro-fceumm/commit/0f6f4190678ede4ddd364427435b4d8850d852e3 or https://github.com/libretro/libretro-fceumm/commit/a76897a920be91e798a2194e9a5ee0f17ed1f16e), so that probably made the save states from previous versions incompatible. Unfortunately this can happen when upstream changes impact save states. If you'd like to build an older version, then you can checkout the source for the emulator from before these changes and see if the old save states load.

Given the new latency reduction feature introduced in RetroArch 1.7.2, that uses save states extensively, I wouldn't be surprised if incompatibilities for save changes will happen for other libretro cores as well.

[xadox]

@mitu Yes, saw that commits, also.

After replacing the fceumm_libretro.so with the one from 4.3 (it is commit 25bb3e6) the old states are working again.

[Drakaen391]

@tpo03 how are you running 4.4 with Jessie???

[mitu]

@drakaen391 You can update your existing Jessie installation and get 4.4.

[tpo03]

@mitu @Drakaen391 Exactly.

[Radiusxe]

Hi,
Is possible to convert save states to new format? Staying on old library is not solution.
With best regards Radius

[mediamogul]

@radiusxe

The best you can hope for is to load the save state from the previous core version and work your way to an area that allows for a normal memory save. Afterwards, update the core load the save and make a new save state. I realize this wouldn't be possible for all games and it's a major hassle, but it's really the only option. It's best to only utilize save states for very casual use and at no time when it's crucial to keep them for long periods of time. Save state formats can change at any time depending on development. You might see an emulator/core keep its format throughout its lifespan, or you might see it change several times a year.