The score of Minecraft is since update 1.18. imported was defective and can no longer be saved. The game can be opened for the first time, but as soon as you exit and save, the saved game can no longer be opened and the game runs with errors. See the pictures below

The save has been in the works for 3 years and there are days of gameplay in the save. If this progress was lost forever I would never play Minecraft again because so much time went into it that it is not sustainable to lose something like that through an update.

I hope you can fix the save and everything will be fine again