Export layers to files only works when you give the file a name first.

[marcelo38653217]

I always got the error message 'Error: The requested action requires that the target document is the frontmost document.' when trying to export multiple layers to files. I figured out that you have to give your PSD file a name first (and save it) before this script works. Photoshop should know this and tell the user he has to give it a name first and save it. 

The error message is not helping at all, since the document was the only open document.

[c.pfaffenbichler]

You are right that the error-message is unrelated to the problem.

But why would you be working on unsaved files to begin with? 

The Script »Export Layers To Files.jsx« is, if I remember correctly, pretty voluminous, but if the issue is a recurring one for you you could try to amend it nonetheless.