Knowledge

ERROR_AUTHENTICATION_FIREWALL_FAILED - 1935 (0x78F)

The computer you are signing into is protected by an authentication firewall. The specified account is not allowed to authenticate to the computer.

Updated: Feb 21, 2026

Technical Meaning

The error code ERROR_AUTHENTICATION_FIREWALL_FAILED (1935, 0x78F) indicates that the specified account is not permitted to authenticate to a computer protected by an authentication firewall. This error suggests that the security policy configured on the system restricts access for certain accounts.

Error Details

This specific error code is returned when an attempt to authenticate fails due to the presence of an authentication firewall, which acts as an additional layer of security beyond standard Windows authentication mechanisms. The firewall may be configured to block or allow specific accounts based on predefined rules.

Usage Context

The ERROR_AUTHENTICATION_FIREWALL_FAILED error typically occurs during user logon attempts or when attempting to access resources protected by the authentication firewall. It is important to note that this error does not indicate a failure in the Windows authentication process itself, but rather a restriction imposed by an external security policy.

Developer Interpretation

Developers should interpret this error as a result of a security policy enforced by the system. When encountering this error, developers should ensure that the account being used for authentication is correctly configured and authorized to access the protected resources. Developers may also need to verify if the authentication firewall rules are set up appropriately.

Related Errors

  • ERROR_LOGON_FAILURE (1326)
  • ERROR_ACCOUNT_RESTRICTION (1510)

    FAQ

    Q: What does the ERROR_AUTHENTICATION_FIREWALL_FAILED error mean?

    A: This error indicates that an account is not allowed to authenticate due to a security policy enforced by an authentication firewall.

    Q: How can I resolve this issue?

    A: Ensure that the account being used for authentication has been correctly configured and authorized. Verify the authentication firewall rules to ensure they are set up appropriately.

    Summary

    The ERROR_AUTHENTICATION_FIREWALL_FAILED error (1935, 0x78F) is a specific error code indicating that an account is not allowed to authenticate due to security policies enforced by an authentication firewall. Developers should focus on verifying the configuration of both the account and the authentication firewall rules.