Hey, sounds like you’re really going through it—losing a heavily modified blueprint like that is rough, especially when it’s tied into so many other parts of your project. Unreal Engine can be picky with file versions, and unfortunately, once a .uasset is saved in a very old or incompatible version, UE 5.4.4 won’t recognize or upgrade it properly.
Copying the old files into the Saved or Engine Content folder won’t work because Unreal checks the internal package version on load. That “Package Version: 0” error usually means the asset was created or saved in an outdated format or somehow got corrupted. If none of your backups have the SunSky asset in a newer version (at least version 214), then sadly, Unreal won’t open them.
You might try opening those backup projects in an older version of Unreal (like UE 4.25 or whichever version the file originally came from), export the SunSky blueprint as a text or JSON file (if you can open it), then import or recreate it in 5.4.4. Otherwise, manual recreation might be the only way forward. I know that’s not what you wanted to hear, but if you ever need help recreating the logic, I’m here to walk through it with you.
Regards