Miracast / Microsoft Wireless Display Adapter not connecting

Your or the Intune / Endpoint Manager managed device suddenly is not connecting to the Microsoft wireless display adapter? Then the problem is certainly with the Windows Defender Firewall, which is blocking the incoming connection of “WUDFHost.exe”.
Fortunately, we can fix this quickly by either creating a firewall rule locally on the device or distributing it with Intune.

This issue does not only affect the Microsoft Wireless Display Adapter.
It affects any Miracast based solution.

The problem

Typical symptoms look like this:

• The device is visible but never connects
• The connection starts and then immediately drops
• Black screen after connecting
• Works on unmanaged devices but fails on hardened ones

This happens with:

• Microsoft Wireless Display Adapter
• Smart TVs with built in Miracast
• Conference room displays
• Any Wi Fi Direct based receiver

In almost all cases the adapter itself is not the problem.

The real root cause

The real cause is almost always a Security Baseline or CIS hardening policy.

Modern enterprise baselines often:

• Enforce only policy defined firewall rules
• Block merging of local firewall rules
• Remove dynamically created inbound rules

Miracast relies on locally created inbound Windows Firewall rules that are added dynamically when wireless display is started.

If local firewall rules are blocked these rules never apply.

As a result the Miracast connection is blocked by Windows Firewall even though the adapter, drivers and network are fine.

Many guides recommend disabling the firewall or turning off the security baseline to fix this. This is not recommended. The baseline itself is correct and important. The only problem is that Miracast requires specific inbound firewall rules that are not included by default.

The solution: Defender Firewall rule via Intune

If your organization is using Intune and users report “The Microsoft Wireless Display Adapter is not connecting.” Can you fix this globally with a simple policy.

In Intune under “Endpoint security > Firewall” we create a new “Microsoft Defender Firewall” ruleset. Alternatively, you can also add the rule to an existing policy.
If you create a new one use a meaningfull name and best is to add a desription for more context as well.

In the next step you now need to add the firewall rule for the inbound Miracast connection.
Click onm “+Add”, define a Name again and with “Edit instance” you can add the Firewall rule like showin in the screenshot and/or table below.

Setting	Value
Interface Types	Wireless
File Path	%SystemRoot%\System32\WUDFHost.exe
Network Types	Domain, Privat, Public
Description	Miracast
Direction	Inbound traffic

After the definition, we assign the rule to a group or all devices and save it.
As soon as the new rule has been applied on the device, the connection to the your Miracast device / Microsoft Wireless Display Adapter should work again.

Create a Defender Firewall rule manually

This won’t work if you have a security policy like the following in place:
- Firewall\Enable Public Network Firewall: Allow Local Ipsec Policy Merge —> False

We create the rule in “Windows Defender Firewall with Advanced Security”. The easiest way to find this is in the start menu with the appropriate search term. Then open the settings as an administrator.

In the “Inbound Rules” we create a new one.

This is for a program and the path to it is “%SystemRoot%\System32\WUDFHost.exe”.

Of course we allow the connections, and we also leave it for all three profiles so that the connection also works in external networks.

Finally, we assign a meaningful name, such as “MS Wireless Display Adapter”. The description is optional. After clicking on “Finish”, you will see the newly created rule in the overview.

Once created, the connection to the Microsoft Wireless Display Adapter will work properly again (hopefully).