We followed the instructions for changing our space theme. After confirming, our space now says "Not Found". Any ideas why using this tool would blow away our space? Here are the instructions from Confluence.
Welcome to the Atlassian Community!
A change of theme is a change of the framework. It has no effect on your data at all. It's about viewing it.
Imagine you've got a copy of a good bok in front of you. It doesn't matter what you view it through, the book is there. If you choose to use a "theme" that totally obscures it, that's fine, but the theme does not affect the data.