How can I find out why my world won't export? Solved!

You might want to try the solutions posted here: https://forums.thesims.com/en_US/discussion/333534/world-export-failed-solution.

If those don't work, then try renaming the file, like Blazeburg1.

Another potential fix is to pull out the Worlds folder and drag to desktop, restart CAW to create a brand new Worlds folder, then put Blazeburg back in and export from newly generated folder.