> For the complete documentation index, see [llms.txt](https://docs.b2core.b2broker.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.b2core.b2broker.com/troubleshooting/sign-in-and-authentication-issues/clients-encounter-not-found-error-after-signing-in-to-the-b2core-ui.md).
# Clients encounter the 404 Not Found error after signing in to the B2CORE UI
## Problem
After signing in to the B2CORE UI and completing 2FA (if enabled), a client encounters the `404 Not Found` error and sees a blank page.
## Possible reasons
This issue may occur if the client doesn't have permissions to view the main menu due to restrictions based on **verification level** or **client type**.
## Solution
To check and update the main menu visibility settings:
{% stepper %}
{% step %}
In the Back Office, navigate to **Promotion** > **Menu**.
{% endstep %}
{% step %}
Ensure that the toggle in the **Visible** column is enabled for the **General** row. If disabled, clients will remain stuck on the **Sign In** page after entering their credentials.
The main menu visibility option
{% endstep %}
{% step %}
Click the **Edit** button in the **General** row to open the details.
{% endstep %}
{% step %}
Check the **Verification level allowance** and **Client type allowance** lists. Make sure the client’s verification level and client type are included in those lists; otherwise, the main menu won't be displayed to that client.
Verification level and client type restrictions for the main menu
{% endstep %}
{% step %}
Click **Save** to apply the changes.
{% endstep %}
{% step %}
Click the **eye** icon located in the **General** row to view the menu tree.
The menu tree
{% endstep %}
{% step %}
Verify that the **Visible** toggle is enabled for all menu items that you want to display in the main menu.
{% endstep %}
{% step %}
For each menu item, click the **Edit** button and check the **Verification level allowance** and **Client type allowance** lists. Adjust them if necessary.
{% endstep %}
{% endstepper %}
The **Visible** toggle must be enabled for the **General** row and all required menu items. In addition, the **Verification level allowance** and **Client type allowance** lists for both the **General** row and menu items must be properly configured to ensure that clients with the appropriate verification levels and client types can access the menu.
---
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