[V7] ISSUE: LAN manager authentication level must be 3 or higher (cannot create MS Exchange mail level backup) [Ahsay Wiki]

[V7] ISSUE: LAN manager authentication level must be 3 or higher (cannot create MS Exchange mail level backup)

Article ID: 5342
Reviewed: 2018-05-24

Product Version:
AhsayOBM: 7.3.0.0 to 7.x
OS: Windows

ATTENTION 1st January, 2022: v7 officially End-of-Life [details]

Problem Description

When creating a MS Exchange Mail Level Backup Set, the following error message is displayed:

LAN Manager authentication level must be 3 or higher.

Cause

The error message suggested that for the domain which the Exchange server reside, the Network security: LAN Manager authentication level policy setting must be set to level 3 or higher (Registry security level), which is one of the following:

Send NTLMv2 response only

Send NTLMv2 response only. Refuse LM

Send NTLMv2 response only. Refuse LM & NTLM

Reference: https://docs.microsoft.com/en-us/windows/security/threat-protection/security-policy-settings/network-security-lan-manager-authentication-level

Resolution

To resolve the issue, please refer to the following steps:

Open Local Security Policy from Administrative Tools.

Under Security Settings, expand Local Policies, Security Options, Network security: LAN Manager authentication level.

Ensure that the setting is configured to use NTLMv2, for example:
- Send NTLMv2 response only
- Send NTLMv2 response only. Refuse LM
- Send NTLMv2 response only. Refuse LM & NTLM

Keywords

lan, manager, obm, ahsayobm, exch, exchange, msexchange, auth, authentication

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