Custom branding theams not working

Hello Yuliia Bashko,

If custom branding themes suddenly stop showing in Microsoft Entra External ID, it usually means the sign‑in request isn’t evaluating the theme or the theme assets can’t be loaded.

Please check the following:

1. Theme ↔ App association – Make sure the branding theme is still explicitly assigned to the exact application you’re testing. Themes apply only to associated apps; otherwise Entra falls back to default/neutral branding.
2. Test via the correct sign-in flow – Launch sign-in using the app/user flow (“Run now”) and not a generic Microsoft sign-in URL.
3. Asset validation – If any image (logo/banner) violates size or format requirements, the page silently falls back to neutral branding. Try a minimal theme (background color + text only) to confirm.
4. Fallback behavior – When custom branding can’t load (asset failure, blocked download, cache), Entra automatically reverts to neutral branding. Check browser DevTools → Network for failed image/CSS requests.
5. Caching – Test in InPrivate/Incognito or another browser/device.

Hi @VEMULA SRISAI

1. App is associated with Theme
2. Tested - as a result the default theme is used and Request URL https://tenant.ciamlogin.com/favicon.ico Request Method GET Status Code 404 Not Found
3. All sizes are within limits
4. Tested in Private tab

Yuliia Bashko The 404 on /favicon.ico from ciamlogin.com is expected and not related to branding theme failures. External ID does not require a favicon for theme rendering, and this request failing does not prevent custom branding from loading.

Since the app is correctly associated and sizes are within limits, the remaining points to validate are:

• Theme applies only to the exact sign‑in flow (app launch / user flow). If the request doesn’t match the app or flow, Entra falls back to default branding.
• Silent fallback behavior is by design. If any branding asset fails validation or can’t be resolved, the service automatically reverts to the neutral theme without error.
• Propagation: Branding changes in External ID can take time to fully propagate across edge endpoints.

At this stage, if the theme consistently falls back to default even with minimal branding (for example, background color only), this points to a service‑side issue and should be raised with Microsoft support from the tenant that owns the External ID configuration.