What am I doing wrong with the FileSystem API?

So I have this page here which I have configured to simply record & plays back audio from the browser: [login to view URL] Right now, it records & plays back audio using MP3 & I believe just a session cache. So a user will click the mic button, record their audio, and then have the option to listen to the audio they recorded as well as a 'Submit' button. I'm trying to get the 'Submit' button to save the file locally to the machine using the FileSystem API, but I don't know what I'm doing wrong. This project will only ever run on this system & will not be online at any point, so it's fine that this API is Chrome specific. According to this site here: [login to view URL] it should provide a pop up at some point that asks if the user wants to allow the FS stuff, but I never get that. In console it just says "Error". I still have all the code up in my example and I guess it "works" but it triggers one of 5 error codes, of which the one it triggers is just "Error". I want to use "Persistent" storage. Looking in Chrome dev tools I can see that the file is correctly recorded but that an 'error 18' happens after that, when submit is pressed, but I don't know what that means. send me a message & I can send you a zipped copy of this site if need be but it's literally just that [login to view URL] file & the javascript inside. Please reply to this message with your favorite food so I know you're not a robot! :~) Just a warning if you're gonna try to test this locally, it doesn't work locally from file:// as a security thing. In Windows you can use '--allow-file-access-from-files' flag to bypass this, I think that running it in a webserver would work as well. I know that there are other ways to save a file & I'm open to suggestions if you have a good idea, but it's very important that the storage is permanent & only asks for permission to store an unlimited files 1 single time... But talk to me about this first - I can't pay you if I think you're fixing the FileSystem & then turn in a different method, I just have to make sure the method I use will be a good fit for this project. I'm hoping to get this done tonight if possible