Lancelotpl-3096 avatar image
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Lancelotpl-3096 asked SunnyQi-MSFT commented

[Windows Server 2019] Failing to connect to a shared folder


I am trying to connect to a shared folder thorugh the "Map new network drive" option. Although checking the "Connect using different credentials" and typing correct credentials this pops up:


If I try to add it through "Add a network location", this issue pops up:


Although I am not logging as a guest, I decided to allow guest loggins following this link:

After modifying the registry and the group policy, there were no more error messages in the SMPClient and SMBServer events, nonetheless the same issue persisted.

What shall i do?
This is the server version:

After turning on password sharing, this is the SMB server Security Event popping up, although providing correct credentials, as I am able to connect through FTP.

User Name:
Session ID: 0x7C00E8000B81
Status: A user has requested a type of logon (e.g., interactive or network) that has not been granted. An administrator has control over who may logon interactively and through the network. (0xC000015B)
SPN: session setup failed before the SPN could be queried
SPN Validation Policy: SPN optional / no validation


You should expect this error when attempting to connect to shares using incorrect credentials.

This error does not always indicate a problem with authorization, but mainly authentication. It is more common with non-Windows clients.

This error can occur when using incorrect usernames and passwords with NTLM, mismatched LmCompatibility settings between client and server, an incorrect service principal name, duplicate Kerberos service principal names, incorrect Kerberos ticket-granting service tickets, or Guest accounts without Guest access enabled

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1 Answer

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SunnyQi-MSFT answered SunnyQi-MSFT commented


Thanks for posting in Q&A platform.

Please confirm if the value of AllowsecureGuestAuth which is under the following registry key was set to 1 :


If the issue still existed, please try to turn on "Password protected sharing" in server 2019 network sharing center to see if the issue can be resolved.


Best Regards,

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Thank you for your answers. The registry is correct, turning on password protected sharing unfortunately does not work.

What other ways are there to debug this issue?

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Thanks for your feedback. Kindly check if Fix2 in the following article can help you:
Please Note: Since the websites are not hosted by Microsoft, the links may change without notice. Microsoft does not guarantee the accuracy of this information.

Best Regards,

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Thank you, that solved it!

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