I discovered this glitch of not being able to place blocks in a certain area of the world, so i tried figuring out how to solve it. After over 10 billion milliseconds pasted, i discovered the fix to this glitch. And now, I'll show you how to fix it.
The way i found this fix is by doing > /testforblock ~ ~ ~ air < inside the non block placeable spot and this happened (attachment 1)
There was apparently a "block" called tile.null.name occupying the block's spot.
So the fix of this is to simply set the block to air done fixed
Hopefully you guys can fix your worlds with this glitch.
Please give me a shoutout if you are re-uploading this.