Gah! The Snap Blocks Fall Apart!

This explains it all:

Do you know what you were doing when that happened?

I was just coding and I clicked the undo button and that happened.

can you replicate what you did to make it happen?

I don't understand.

That is not at all normal. The undo button is weird normally.

yeah, but I've never seen this happen before

Well it could be a new bug.

I cannot reproduce this doing what you say you did. Frankly, this looks like you've switched to dev mode to take those blocks apart.

it didn't worked as you did it.