Facebook API: (#100) No matching user found

Question

I spent whole days to try to figure out this error, I also notice there are similar questions with the same message, but I'm totally not sure I find the answer in there, so if someone could point out or give any tip into my problem, I totally appreciate that.

I'm making the request to send a message from a Facebook page A to a user X (by userId) who makes a comment on a post of FB Page A, through a testing FB App name MyApp. I am trying this on Facebook Graph Explorer.

I got the user Id by fetch the list of comments in a post in the Facebook Page, but I totally could not send the message.

Here is the error

{
      "error": {
        "message": "(#100) No matching user found",
        "type": "OAuthException",
        "code": 100,
        "error_subcode": 2018001,
        "fbtrace_id": "H3yMO0RWaDy"
      }
}

Here is the my track

MyApp has been setup webhook OK, because it is not published yet for the testing purpose (unapproved app), so I have to add the user X account into tester pool of MyApp (the message that I try to send is also this user X)
I logged into user X to make a comment on a post in the FB Page A
On Graph Explorer, I selected Application: MyApp, and get Page Access Token of FB Page A, I performed two following requests

3.1 /{page_id}_{post_id}?fields=comments With this, I can get the list of existing comments in FB Page A, here is the output:

{
    "comments": {
        "data": [
                  {
                    "created_time": "...",
                    "from": {
                      "name": "User X",
                      "id": "123456789" // this is the user Id that I would take to send the message to
                    },
                    "message": "Sample comment from User X",
                    "id": "..." // {page_id}_{post_id}
                  }
                ],
                "paging": {
                   ....
                }
              },
              "id": "..." // {page_id}_{post_id
    }
}

3.2 {page_id}/messages: I am trying to send a message from FB Page A to user X with the user Id that I got from 3.1 step

recipient: {id: "123456789"} // there seems be a problem with this id that I got from step 3.1, FB cannot find the user id with this number
message: {text: "hello"}

I'm also acknowledged about the app/page scoped id for user.

I have already subscribed MyApp to the FB Page A with API (/{page_id}/subscribed_apps)

Facebook API v2.10

I have no clue what's wrong.

Facebook API: (#100) No matching user found

1 Answers