Stream lists are empty

Bug report

• I understand the difference between Streamlink and Streamlink Twitch GUI.
• This is a bug report and I have read the contribution guidelines.

Environment details

Operating system and version:
Windows 10

Streamlink Twitch GUI version:
1.9.1 NW.js: 0.42.3 Architecture: x64

Streamlink version:
streamlink 1.3.1

Configuration details:
I just upgraded from 1.9.0 to 1.9.1 to see if the error was fixed but the error occures in both versions

Description

When I open Streams in the left menu, all I get is:

Top Streams

The returned list of top streams is empty.

When I open Games, I can see the list of all games being streamed. However, if I open any of them, I get the same result:

Dota 2

The returned list of streams of this game is empty.

Any stream under Featured works correctly.

Two days ago, everything worked smoothly with the previous versions Streamlink Twitch GUI 1.9.0 and Streamlink 1.3.0 so I suspect it’s an API change from Twitch.

Expected / Actual behavior

I expect to see all streams under Streams and all related streams when selecting a game under Games

See description above for actual behaviour.

Reproduction steps

1. Open Streamlink Twitch GUI
2. Click Straems in the left menubar under Browse
3. See empty list

Log output

[2020-02-21T20:37:46.752Z][debug][Application]
Parameters
{
    "_": [],
    "tray": false,
    "hide": false,
    "hidden": false,
    "max": false,
    "maximize": false,
    "maximized": false,
    "min": false,
    "minimize": false,
    "minimized": false,
    "reset-window": false,
    "versioncheck": true,
    "version-check": true,
    "logfile": true,
    "loglevel": "debug",
    "l": "debug",
    "launch": "",
    "goto": ""
}

Additional comments, screenshots, etc.

[bastimeyer]

Issue reported on the Twitch dev forums: https://discuss.dev.twitch.tv/t/kraken-language-and-broadcaster-language-request-parameters-partly-broken/24214

[alkim0]

Note that the language parameter now works according to https://github.com/twitchdev/issues/issues/66. However, the broadcaster_language still seems broken. It seems it would be prudent to change language filtering settings from broadcaster_language to language.