Windows App 0x407 Data Encryption Error after updating to macOS Sequoia 15.0.1

Question

I had waited for the release of macOS Sequoia 15.0.1 to update, and now after updating I'm having issues with the Windows App disconnecting my Remote Desktop sessions frequently with the message: "Your session ended because of a data encryption error. If this keeps happening, contact your network administrator for assistance. Error code: 0x407"

To be clear, I can connect to my machine - but after anywhere from 1-10 minutes get disconnected with that data encryption error message.

I originally still had the old Remote Desktop app installed and was getting this error - but had forced the upgrade to the Windows app to see if that would help, but am still not having any luck.

No idea if it's relevant, but we need to be connected to VPN to connect to Remote Desktop sessions and are on Cisco AnyConnect version 4.10.08029 (which apparently does not explicitly support macOS Sequoia).

Answer 1

I turned on logging for Windows App and re-enabled the macOS Firewall. Immediately got the error and see this in the logs:

RDPSECURITYFILTER(ERR): Disconnecting with disconnect reason: SSL_ERR_DECRYPTION_FAILED

/Users/runner/work/1/s/source/stack/libtermsrv/rdp/LegacyXPlat/Filters/SSL/SslFilter.cpp(791): DisconnectWithErrorCode()

E|2024-10-09 16:52:21.8990 -05:00|:0 {c704aeb6-bbfe-4e20-8597-aa78148e0000} <0x16f8d3000> RDPSECURITYFILTER(ERR): Caught a TLSFilterException during send or receive: SSL_read failed with Decryption (or bad MAC) error. error:0A000119:SSL routines::decryption failed or bad record mac . ErrorCode: DecryptionFailed

The macOS Firewall does appear to be the cause of the issue.

Answer 2

Hello,

You can try to disable / enable NLA and confirm if it will resolve your issue as well.

Open gpedit.msc applet.

Navigate to Computer Configuration -> Administrative Templates -> Windows Components -> Remote Desktop Services -> Remote Desktop Session Host -> Security.

Enable Require use of specific security layer for remote (RDP) connections and select RDP as Security Layer.

Disable Require user authentication for remote connections by using Network Level Authentication policy.

Reboot Terminal server.

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Answer 3

I was able to solve this issue by "accepting the unsigned certificate" when initializing the RDP connection on my Mac to the Windows VM. No further issues noted.

Windows 11 Pro

Mac OS Sequoia 15.1.1