TOPIC:

I think the problem with th OP is that the projects were not published.

The second poster mentions also issues, but these are completely different. So it would have been best to create a separate topic.

Without extra information it is difficult to figure out what is happening.
An external disk sounds like trouble. Is it an NTFS disk?

I suspect permission issues. You could try to set $developer to true around lin 43 in config.php and see if you can identify the issue in the apache error log

That wasn't the issue at all. Publishing was one of the first things I tried in fact.

I just figured it out today. If I used a custom Xhibit theme, it wouldn't export properly, and sometimes, wouldn't even export at all. Using one of the built-in themes works.

Thank you for commin back to us. Now we can try to fix that issue.
Did you custom theme happen to contain an '_'?

If you are asking about the name of the theme, there are no underscores. The name has dashes though.

What version (exactly) are you using. Since version version v3.13.4-3 characters _ and - are allowed. Befroe that version, the export does not work.