The login is from an untrusted domain and cannot be used with integrated authentication

The error message "The login is from an untrusted domain and cannot be used with Integrated Authentication" typically indicates that there are issues with the trust relationship between the domains involved. This can happen after updates or changes to the network configuration, such as the Windows patches you mentioned.

To resolve this issue, consider the following steps:

1. Check Domain Trusts: Ensure that the domains are properly trusted and that the trust relationship has not been disrupted. You may need to verify the trust settings in Active Directory.
2. User Group Membership: Make sure that users from the remote domain belong to a group in the SQL Server domain. If using a domain local group, this could lead to issues when trying to connect from another domain.
3. Selective Authentication: If selective authentication is enabled, ensure that the users from the trusted domain have the necessary permissions to authenticate in the SQL Server domain.
4. Service Principal Name (SPN): Verify that the SPN is registered correctly for the SQL Server service account. You can use the setspn command to check and register SPNs if necessary.
5. Local Security Authority Subsystem Service (LSASS): If there are issues with LSASS, it may not be responding properly, which can lead to authentication failures. Check the system logs for any related errors and consider restarting the service if needed.

If the issue persists after these checks, further investigation into the network configuration and domain settings may be required.

References:

• Consistent authentication issues in SQL Server
• Local security subsystem errors in SQL Server