Hi,

i had the same problem - after enable enableExternalDirectory the app was not running.
When you open the chrome://extensions tab and inspect the view of the main file (app_main.html) in the console i saw error "Operation requires fileSystem.directory permission". Then edited the manifest.json by adding "directory" to the fileSystem part. After reload the app was started with no problems. So check which file system permission you need and add it to manifest.json

Here is how my manifest look like now (default one is only with "write") :
{
"fileSystem": [
"write",
"directory"
]
}

Stefan

Thank you very much,Mr. countnazgul!
With your help, a bbs of China post a tutorial about how to call for the SD card, and we have a joke: Google is the hope of human beings! :-D

@yaomingshiwo 您好，我现在也遇到了同样的问题，请问您是怎么解决的？