Unable to deploy apps to the HoloLens since October, "DEP 6957: Failed to connect to device using Universal Authentication"

Question

I was able to deploy apps to the headset with no problem till October, but for the last month or so have simply not been able to connect using Visual Studio. I've tried deploying to multiple headsets from multiple PCs (all of which worked fine before), but now get this error:

Error DEP6957: Failed to connect to device '169.254.80.51' using Universal Authentication. Please verify the correct remote authentication mode is specified in the project debug settings. COMException - Exception from HRESULT: 0x801C0003 [0x801C0003]

This happens for both USB and remote connections (I have USB Device Connectivity installed in Visual Studio). Visual Studio usually prompts for a PIN when deploying to a headset for the first time, but even after I unpair the device and restart both the device and the computer I am never prompted for a PIN now. I also tried clean-flashing the device, but that didn't work either.

I've used both Windows 10 and 11, and tried to deploy multiple apps (some of which were built last year, and worked fine on the device until now). The headset is detected as a remote machine (target) from Visual Studio, and the Device Portal works with no problem.

I'm using Visual Studio 2019, Unity 2020.3.28f1, and the headsets' build is 22621.1402.

Answer 1

Hello, Welcome to Microsoft Q&A,

First, please ensure that your development environment is Visual Studio 2022, and check if the necessary workloads are installed on VS according to the following link - Install the tools - Mixed Reality | Microsoft Learn.

If you are pairing for the first time on an unpaired computer, make sure to select the Debug or Master build configuration. Then, select "Start Without Debugging" to build and deploy.

For the details of deployment, you can refer to Using Visual Studio to deploy and debug - Mixed Reality | Microsoft Learn.

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