I seem to be experiencing an issue when creating the Voice Script. It creates the file in the AGS folder but the .txt file is blank, apart from the header:
*** All text lines, in order of appearance in the scripts ***
I'm baffled?
I just figured it out.
1. Use "File>Auto Number Speech Lines" to add speech numbers to all your dialogue,
2. Then re-create your voice acting script by clicking "File>Create Voice Acting Script...".
Hope that helps.