Minecraft → World with extended height deactivated?

Pi
- in Worlds
1

For some time now I have not been able to open two of my worlds because it says "The loading of the worlds with extended height is deactivated". Does any of you know how I can change that? The version with which I opened the worlds is 21w17a, so, as I said, I can no longer open them. I'm really looking forward to any helpful answer (and maybe an explanation, if you can change it). If more information is required, just write!

gl
1

Try an older snapshot version