We've had a couple of reports of people getting error messages like this:
***
We found the following errors:
We found the following problems with your files:\n
- The file chapter1.txt is referenced in either Book.txt or Sample.txt or Subset.txt, but does not exist
- The file chapter2.txt is referenced in either Book.txt or Sample.txt or Subset.txt, but does not exist
- The file chapter3.txt is referenced in either Book.txt or Sample.txt or Subset.txt, but does not exist
***
Here's a screenshot of what this looks like in email:
If you see an error message like this, it is probably caused by a bug in our error reporting system, and you can ignore it.
Just to be safe, you might want to double-check your latest preview to make sure there is no real issue here, but there almost certainly is not, and this is just a Leanpub bug.
We're sorry for the inconvenience! This is on our list of things to fix.