There’s no word limit imposed by the plugin, but it’s possible that the larger post —?especially if there’s a lot of media —?might be running out of memory on your server.
When you attempt to export the 6,000+ word article to HTML from Airstory (e.g. “Publish > HTML” within the Airstory application), does Airstory render the HTML as expected? Under the hood, Airstory is using the same HTML rendering for that HTML markup as it is for the WordPress export, but the WordPress plugin has to do some work on its end to do things like import media.
If you don’t mind, could you please send the system report (from the bottom of Tools > Airstory in WordPress) to sgrunwell [AT] liquidweb [DOT] com? This will give me a high-level look at your system specifications, as well as any plugins that might be conflicting with the import process.
