Error validating application
And it doesn't even list the app name in the list of apps (left pane of the dashboard).
When we checked the error_log in the server, the last message is: Why Facebook automatically deleted the app?
Turns out, the phone was connected to a Wifi network without internet access.
As soon as I connected the phone to another wifi with internet, the app installed fine.
BTW Yesterday I discovered if I send a request to /me/accounts with long-term token, list returns with long-term tokens.
I've tested with this: developers.facebook.com/tools/debug/access_token? q= Scenario 5: Page Access Tokens When a user grants an app the manage_pages permission, the app is able to obtain page access tokens for pages that the user administers by querying the [User ID]/accounts Graph API endpoint.
When working with an access token, you may need to check what information is associated with it, such as its user or expiry.
To use the API, you can issue a Graph API request: time passed to your App along with the access token, your app may only learn that a given token has become invalid is when you attempt to make a request to the API.