ERRCONNECT_SECURITY_NEGO_CONNECT_FAILED (0x0000000C)

Hello

Sorry to hear it's not working for you. A full session log should show us what's going on, you can enable it by following these instructions.

Once you have the log, you can send it to me by PM.

Please let me know if something isn't clear or you have further questions

Kind regards,

session log sent by PM

Hello again

Thanks, I received the log.

It's not an error I've seen before, but it relates to parsing a structure sent by the server. Can I know more about the server? For example, what OS is it running?

It's a bit of a shot in the dark without more information, but in the "Authentication" tab of the RDP session settings, try disabling "Enable Network Level Authentication (NLA)" and "Enable Transport Layer Security (TLS)" leaving _only_ "Enable Remote Desktop Protocol Security (RDP)" checked.



Please, let me know if something isn't clear or you have further questions

Kind regards,

Hi,

I've tried without success.
I can't give any details about the server because it's the first time connecting to it (new customer).

I've tried legacy engine also and same result...

let me know if I can help in any way to diagnose this issue.

I have exactly the same issue since updating to 2024.1.6.2 on MacOS. This is currently only happening when trying to connect to a server running Windows Server 2022, but I have other Windows Server 2022 boxes that I can still connect to with no problems.

I have not yet been able to isolate what the difference is. I can connect to the box using the Microsoft RDP client with no problem at all.

I don't have that luck! not even the Microsoft RDP client works.

I have exactly the same issue since updating to 2024.1.6.2 on MacOS. This is currently only happening when trying to connect to a server running Windows Server 2022, but I have other Windows Server 2022 boxes that I can still connect to with no problems.

I have not yet been able to isolate what the difference is. I can connect to the box using the Microsoft RDP client with no problem at all.

Hello

Can you follow the instructions I have to telmop up thread and generate a log file, and send it to me?

Thank you and kind regards,

Thanks Richard,

I've sent you a log file. However, I just tried enabling NLA, and this has allowed me to connect. I think there may have been a coincidental change around the time that I upgraded RDM that caused the target machine to also require NLA - maybe a Windows Update re-enabled this option or something.

Sorry for the confusion!

Thanks Richard,

I've sent you a log file. However, I just tried enabling NLA, and this has allowed me to connect. I think there may have been a coincidental change around the time that I upgraded RDM that caused the target machine to also require NLA - maybe a Windows Update re-enabled this option or something.

Sorry for the confusion!

Hello

Good news! NLA is recommended in every case if your environment supports it, the older RDP security methods (RDP enhanced security) are a significant security downgrade.

Thanks and kind regards,

I don't have that luck! not even the Microsoft RDP client works.

Hello again

I wouldn't expect the legacy engine to work better, in fact I think it's slated for removal currently. It's based on a very old version of our RDP module that we can't reasonably support any more.

Sadly if even the MS RDP client won't connect, I don't think I can offer much more guidance without further information about the server environment. The connection is failing very early, it looks like the server sends bad or unexpected data as part of the security negotiation. We would at least need to know what the server environment is (the most likely explanation I can think of is that this isn't a Microsoft or at least RDP compliant server or that there's some additional software / infrastructure involved).

Please, let me know if you can gather any more information.

Thanks and kind regards,