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After installing VS2019 16.5.1 and 16.5.2 I receive a message that Windows Defender has locked some features of Xamarin.Messaging.Broker and asking if I should allow it.

Normally I would as it seems to be part of Visual Studio but this executable is located in my appdata\local\temp file, which I would not expect it to be. Searching the net for info about this yields little in the way of good information.

Does anyoe know what it does and why on earth would you put an exe in the local user temp?

John Mackerras
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  • Hi , you mean before 16.5.1 it not wants firewall access ,right ? – Junior Jiang Apr 02 '20 at 05:54
  • yes, that's right. – John Mackerras Apr 02 '20 at 09:32
  • I wonder if this is a bug in a recent VS update? I had the same issue, and searching for it only turned up this recent question of yours. – cost Apr 07 '20 at 17:01
  • I got this message out of nowhere even though I use VS daily, I haven't updated VS in a couple weeks, and I don't even have a Xamarin project currently running. – Post Impatica Nov 12 '20 at 18:50
  • Me too, Post Impatica. Maybe we should post it to an MS forum. – user3761340 Mar 20 '22 at 05:42
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    I got this message first time today in VS2022 17.1.2. After I clicked up the Toolbox window for the first time in years. – Nicolas Lewentorp Mar 30 '22 at 07:24
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    Same here, v17.1.2... what's funny (and sad) is an MS _employee_ posted this as an issue [here](https://developercommunity.visualstudio.com/t/asks-for-network-request-permission-when-opening-t/1167297) and was blown off with "closed-not a bug" and effectively zero useful information (in badly broken English). I guess it's "nice" to know that we "little people" aren't the only ones who get the cold shoulder on VS issues. – McGuireV10 Apr 03 '22 at 14:43

3 Answers3

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My message appear exactly after upgrade 16.5.0 to 16.5.3, We all see this message in 16.5.2 version and above.

So as far as we know this happened because microsoft add something new in 16.5.2 and above, It can't be anything except microsoft work since we all have seen this firewall message.

My file was in C:\users\username\appdata\local\temp\xamarin\xma\broker.local\16.5.000.533\broker.exe

This access will add a record in firewall advanced "Inbound Rules" Which means grant an access from outside to our PCs on UDP/TCP.

Conclusion :

Personaly i allowd this file in firewall because i have tons of problems in xamarin (special to connect to Mac) and i don't want to add more, I suggest you all do the same.

Ali Poustdouzan
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    *Personaly i allowd this file in firewall because i have tons of problems in xamarin (special to connect to Mac) and i don't want to add more, I suggest you all do the same.* Cannot disagree with that logic :) – Ruslan Oct 26 '20 at 10:07
  • Still an issue with the path "%USERPROFILE%\appdata\local\temp\xamarin\xma\local\broker\17.2.0.177\broker.exe". I don't use Xamarin directly, but I got the request for access when I started using Simple.Wpf.Terminal. – Grault Jul 12 '22 at 15:59
  • Why is it necessary to allow the firewall access? i.e. what won't you be able to achieve if you deny access? Also the q about an exe in the local temp dir is still outstanding. – john blair Sep 09 '22 at 16:13
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I don't know why it would be in that location, but this article lists the endpoints to allow for a xamarin firewall configuration. Perhaps it might assist in some way.

https://learn.microsoft.com/en-us/xamarin/get-started/installation/firewall

Pete C TT
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    That article is about outbound connections. It does not explain why the Xamarin Broker needs to allow inbound connections. – palota Feb 18 '22 at 09:13
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In VS2022 I just had this security alert just as I went to open the toolbox to add a Button to a new WPF project.

**Windows Defender Firewall has blocked some features of this app**

Name: Broker
Publisher: Xamarin
Path: C:\users\username\appdata\local\temp\xamarin\xma\local\broker\17.3.0.288\broker.exe

Allow Broker to communicate on these networks:
✔ Private networks, such as my home or work network

I refused it.

FreddyFlares
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