I had just built a function to update text by adding a clone under another one and updating its text. Then tried to add functionality to when the the top text box is removed move all clones up. But when I tried to copy and paste a couple lines of code..
First, it only copied 2 of the 7 lines.
When I pressed CTRL + Z it went back to the stone age, removing hours of work. So I had to reload from a saved copy which didn't have the function I was just working on.