Minecraft space on PS4 used up?

Dear Good Question Community,

When I want to transfer my old Minecraft worlds to the new Bedrock version on PS4, I keep getting the following message: "You have almost used up your storage space! Minecraft restricted access to this function until you freed up additional storage space." The funny thing is that I used exactly 108.4 / 408.5 GB, so I still have 300 GB free. Can anyone tell me what to do?

This is because you may have too many worlds on the old minecraft version