I made a dimension.
It was crazy.
I took it out, disassembled it, changed it a little, and reassembled it.
I put it back into the builder.
It built up to 99% and then the machine just vanished, taking the dimension inside it with it.
It is just gone.

Ok it looks like the server deletes blocks that are about to crash it so that what happened there.

Hmm, that's weird. Do you also know what the crash was? Does the server keep a log of that somewhere?

Closing due to lack of information.