Usage of the mobage site for Granblue Fantasy (returns to login loop after successful login attempt)

Brave Browser Web Compatibility
6

@flateric15

Try …

In a Brave Browser New Window, go to:

brave://settings/content/siteDetails?site=https%3A%2F%2Fgranbluefantasy.jp

If you see both buttons: Delete data and Reset permissions then click both. If you only see one of them, click that button. Then scroll down to, and Allow JavaScript.

Repeat those steps for:

brave://settings/content/siteDetails?site=https%3A%2F%2Fgame.granbluefantasy.jp
brave://settings/content/siteDetails?site=https%3A%2F%2Fwww.granbluefantasy.jp
brave://settings/content/siteDetails?site=https%3A%2F%2Fmobage.jp
brave://settings/content/siteDetails?site=https%3A%2F%2Fconnect.mobage.jp
brave://settings/content/siteDetails?site=https%3A%2F%2Fwww.mobage.jp

Next, in a Brave Browser New Window, go to: ‘brave://settings/cookies’ and Add:

  • [*.]granbluefantasy.jp
  • [*.]mobage.jp

Next, in a Brave Browser New Window, go to: ‘brave://settings/content/braveShields’ and Add in the Shields Down section:

  • granbluefantasy.jp
  • game.granbluefantasy.jp
  • www.granbluefantasy.jp
  • mobage.jp
  • connect.mobage.jp
  • www.mobage.jp

Overall, the purpose is to clear what may be some “stale” site data, and then arrange for endurance of some Shields settings.

Be sure to RESTART Brave Browser.

Your issue details that I gave to ChatGPT on July 3rd:

Brave Community member reports:

  • Browser enters into a login loop
  • website in question: https://game.granbluefantasy.jp/
  • issue presents with default Brave Shields
  • disable Brave Shields - does not help
  • no specific Brave Shields adjustements seem to help
  • site works as expected with Chrome
  • Brave Browser version Brave 1.91.172 (64-bit) Chromium: 149.0.7827.115
  • Windows OS

Game is accessed via the link https://game.granbluefantasy.jp/

Game functions well with the latest Chrome and de-googled Chromium browsers on Windows desktop, Android and iOS too.

The site has a very bad track record for needing several workarounds even in Chrome to work properly.

Game was created in 2014 and since then there have been basically very few adjustments to the web-engine it has been running on.

Site uses a third party cookie from the site https://connect.mobage.jp/ for login.

Usual login process:

  1. Accessing the site via game .granbluefantasy.jp/ and clicking onto the orange button

  2. A new page appears with 3 different login choices. I have a registered account on the first site, that works flawlessly.

  3. By clicking the first Icon (“mobage”) and then OK, you are redirected to connect.mobage.jp.

  4. After entering your login details (e-mail and password) and then clicking on the login button, you are redirected to a page confirming successful login.

  5. On the page you have to click on the RETURN button to go back to the game

  6. After this, the page redirects you to the game: [IMAGE of the game, and URL: game.granbluefantasy.jp/#top]

Problem is, that after this successful login, my page (see above) appears and looks like it functions, however, the browser returns to step #1 to login. This error does not happen with Chrome or Chromium.

I have tried to erase all temporary files (including cookies) and then tried to turn off the shield, but it didn’t work. After that I have deleted every temporary file again and added the hosts game.granbluefantasy.jp and connect.mobage.jp to allow third party cookies and all tracking cookies, disabled ad protection too, but it still goes to the same login loop.

This member of the Brave Community included a screenshot, that I transcribed:

Brave Browser Developer Tools > Network > Console:

Error with Permissions-Policy header: Unrecognized feature: ‘attribution-reporting’
Error with Permissions-Policy header: Unrecognized feature: ‘private-aggregation’
Error with Permissions-Policy header: Unrecognized feature: ‘private-state-token-issuance’
Error with Permissions-Policy header: Unrecognized feature: ‘private-state-token-redemption’
Error with Permissions-Policy header: Origin trial controlled feature not enabled: ‘join-ad-interest-group’
Error with Permissions-Policy header: Unrecognized feature: ‘run-ad-auction’
Error with Permissions-Policy header: Unrecognized feature: ‘browsing-tops’
GET https://www.datadoghq-browser-agent.com/us1/v4/datadog-rum.js net::ERR_BLOCKED_BY_CLIENT (index):14

10 Error with Permissions-Policy header: Unrecognized feature: ‘attribution-reporting’
10 Error with Permissions-Policy header: Unrecognized feature: ‘private-aggregation’
10 Error with Permissions-Policy header: Unrecognized feature: ‘private-state-token-issuance’
10 Error with Permissions-Policy header: Unrecognized feature: ‘private-state-token-redemption’
10 Error with Permissions-Policy header: Origin trial controlled feature not enabled: ‘join-ad-interest-group’
10 Error with Permissions-Policy header: Unrecognized feature: ‘run-ad-auction’
10 Error with Permissions-Policy header: Unrecognized feature: ‘browsing-tops’
Uncaught ReferenceError: IdentifyProvider is not defined (index):28
at (index):28:1

Failed to execute ‘postMessage’ on ‘DOMWindow’: The target origin provided (‘https://connect.mobage.jp’) does mobage-jssdk-client.3.10.1.min.js:2
not match the recipient window’s origin (‘https://game.granbluefantasy.jp’).

ChatGPT response to that:

What’s most likely happening

The login depends on a cross-domain session between:

During step 3–5, Mobage sets authentication cookies and/or storage, then redirects back.

In Brave, one of these is likely failing:

1. Third-party cookie / storage partitioning still blocking login

Even if Shields are off, Brave can still:

  • partition storage between connect.mobage.jp and game.granbluefantasy.jp
  • block “third-party” cookies unless explicitly allowed at browser level

Result: login succeeds, but the game never “sees” the session → loop back to login.

2. Script required for session handoff is blocked

This line is a big clue:

GET https://www.datadoghq-browser-agent.com/... net::ERR_BLOCKED_BY_CLIENT

That confirms something is still actively blocked at the browser level (Brave Shields global rules, aggressive adblock filter, or a filter list).

More importantly:

Uncaught ReferenceError: IdentifyProvider is not defined

That usually means a critical JS SDK from Mobage didn’t load, not just analytics.

So the login completes visually, but the client-side session bootstrap never finishes.

3. Cross-origin messaging partially fails

This one:

postMessage ... origin mismatch

is often normal in SSO flows, but combined with missing SDK scripts, it becomes fatal.