# Sign-in & authentication issues

{% content-ref url="sign-in-and-authentication-issues/clients-encounter-not-found-error-after-signing-in-to-the-b2core-ui" %}
[clients-encounter-not-found-error-after-signing-in-to-the-b2core-ui](https://docs.b2core.b2broker.com/troubleshooting/sign-in-and-authentication-issues/clients-encounter-not-found-error-after-signing-in-to-the-b2core-ui)
{% endcontent-ref %}

{% content-ref url="sign-in-and-authentication-issues/clients-experience-sign-in-issues-on-b2core-mobile-app" %}
[clients-experience-sign-in-issues-on-b2core-mobile-app](https://docs.b2core.b2broker.com/troubleshooting/sign-in-and-authentication-issues/clients-experience-sign-in-issues-on-b2core-mobile-app)
{% endcontent-ref %}