I've seen a few open issues with people reporting issues using localMusic. I have found that files with & in the filename cause the "On this device" selection to do nothing. The app is still fully responsive, but "On this device" does nothing. When I remove & from the file names of all files in the local music folder, then "On this device" immediately goes to the full listing of files. I have shown this to be successful for a local music folder with about 30 files, none with &; however, when I then jump straight to a local music folder with 16,000 files and no &, I still get no response from "On this device". So it may be that there are just too many files to list; but it also may be that there are other characters than just the & that are causing "On this device" to not behave as expected.