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.

Table of Contents

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 policy.

In Endpoint Manager under "Endpoint security > Firewall" we create a new "Microsoft Defender Firewall" ruleset. Alternatively, you can also add the rule to an existing policy.

Intune Defender Firewall rules

We give the new policy a name and optionally a description.

Intune Firewall rules Profile

In the newly created or your existing rule we now add a new firewall rule.
(If you don't see the "add" item, you have to press the small arrow on the right.)

Intune new Firewall rule

We usually define the name "MS Wireless Display Adapter", optionally a description, the direction "In" for incoming, as the action "Allowed" and include all three network profiles.
So that the EXE is not blocked, we add it under "File path": %SystemRoot%\System32\WUDFHost.exe
We can leave the other controls as they are.

Intune Firewall rule Microsoft Wireless Display Adapter

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 Microsoft Wireless Display Adapter will work again.

Create a Defender Firewall rule manually

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.

open Windows Defender Firewall with Advanced Security

In the "Inbound Rules" we create a new one.

new inbound rule

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).