Swagger UI 2.1 Stuck "fetching resource list" - json

Question

I have a RESTful API that I have created recently and I won't remember how to use it in a few months. I decided to document my API using Swagger, however I'm going crazy.
I used http://editor.swagger.io/ to create the YAML file that I then convert into a JSON file Swagger can use. When I put file into Swagger UI it just gets stuck at fetching resource list: localhost/swagger.json and the console says Uncaught TypeError: Cannot read property '$ref' of undefined .
I'm using version 2.1.0-alpha.5 of Swagger UI.
Here is my spec file:
swagger: '2.0'
info:
title: TITLE
description: BLAH, BLAH, BLAH, ETC
version: "1.0b"
host: api.example.com
schemes:
- http
basePath: /v1
produces:
- application/json
paths:
/match.json:
get:
#summary: Match Data
description: Used for getting data about a match
parameters:
- name: id
in: query
description: The match ID of from a game
required: true
type: integer
format: int32
- name: key
in: query
description: API key used for authentication.
required: true
type: string
responses:
200:
description: Returns match data
schema:
type: array
items:
$ref: '#/definitions/MatchData'
default:
description: Unexpected error
schema:
$ref: '#/definitions/Error'
definitions:
MatchData:
properties:
info:
type: integer
format: int64
description: General information about the match
time:
type: integer
format: int64
description: Information about the start/end time
stats:
type: array
format: int64
description: Stats about the match
Error:
required:
- errorID
- message
properties:
errorID:
type: string
description: Error ID.
message:
type: string
description: Information about the error.

Answer 1

I've tested your spec, and while I'm not getting the same error you do, the spec is indeed invalid.
If you look at #/definitions/MatchData/properties/stats, you'll see that you define the type: array but you don't provide an 'items' property next to it to say which array it is (and that's mandatory). You may have intended to use type: integer like the properties above it, which goes along with the format: int64.
Since I don't know what you intended to provide, it's difficult to give an accurate solution, but if you add a comment with what you intended to do, I could provide a more detailed answer.
Upon some additional testing, I discovered that there's a bug in the UI. After you make that modification and the spec loads, the operation itself will not expand unless you click on the Expand Operations link. I've opened an issue about it, feel free to follow it there.

Answer 2

This problem can be due to some indentation errors in the yaml file which actually did not show up in the Swagger editor. Check all your definitions and whether they are getting displayed as expected in the preview that you can see in Swagger editor (especially check MatchData).
You can also try giving:
responses:
200:
description: Returns match data
schema:
type: array
items:
schema:
$ref: '#/definitions/MatchData'

Answer 3

For our case, we used Swagger-php and we have:
* #SWG\Response(
* response=200,
* description="app response"
* #SWG\Schema(
* type="array"
* )
* ),
but we missed " * #SWG\Items(ref="#/definitions/pet")". After removing "#SWG\Schema(", it works e.g.
* #SWG\Response(
* response=200,
* description="app response"
* ),