Remote Desktop app on Mac not working anymore under macOS 14.2.1

Question

Remote Desktop app on Mac not working anymore under macOS 14.2.1

Hyperion 15

Hi

I can't anymore use the remote desktop app on mac. On macOS 14.2.1 I always get the following error:

Unable to connect

We couldn’t connect to the remote PC. Make sure the PC is turned on and connected to the network and that remote access is enabled.

Error code: 0x204

But I can connect to the windows PC when using the remote desktop app on my iPhone or iPad. Only on Mac it doesn't work, so the PC side works. And it worked on my Mac before.

Greetings

Patrick

Hasan Zaheer 5 Reputation points

2024-03-11T11:02:07.4733333+00:00

The error code 0x204 indicates that the macOS Remote Desktop app cannot connect to the remote PC. To troubleshoot, ensure both devices are on the same network with stable internet connections, verify remote access settings on the Windows PC, check firewall and antivirus settings, update macOS and the Remote Desktop app, reset Remote Desktop preferences, and if necessary, reinstall the app. If the issue persists, double-check the IP address or hostname of the remote PC and consider trying alternative Remote Desktop clients for macOS.

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Your answer

Hasan Zaheer 5 Reputation points

2024-03-11T11:02:07.4733333+00:00

The error code 0x204 indicates that the macOS Remote Desktop app cannot connect to the remote PC. To troubleshoot, ensure both devices are on the same network with stable internet connections, verify remote access settings on the Windows PC, check firewall and antivirus settings, update macOS and the Remote Desktop app, reset Remote Desktop preferences, and if necessary, reinstall the app. If the issue persists, double-check the IP address or hostname of the remote PC and consider trying alternative Remote Desktop clients for macOS.

Answer 1

Richard Hornbaker 10

I am seeing this issue with a new installation of Remote Desktop 10.9.10 on macOS 14.6.1. The problem is not with the DNS server - it is with the Remote Desktop client querying the wrong DNS servers.

Using Wireshark, I can see that DNS queries are not being sent to the two DNS servers shown in macOS as learned via DHCP - instead, Remote Desktop (and only this product) is sending DNS queries to two DNS servers that we decommissioned last year, and which have not been learned via DHCP since then.

Why is the Remote Desktop client not using the macOS DNS server settings?

Rusty Morgan 5 Reputation points

2024-09-18T13:15:48.0533333+00:00

I'm seeing the same behavior today. macOS Sequoia 15.0 and Microsoft Remote Desktop 10.9.10(2327)

This worked fine all day yesterday (Tuesday). I had updated to macOS 15 on Monday so that shouldn't be the problem.
Richard Hornbaker 10 Reputation points

2024-09-18T21:55:10.6666667+00:00

Eureka! I found a fix, at least for my scenario - hopefully this helps someone else...

The short version: look in /etc/resolvers/ for the remnants of config files from the Leopard era that have old/invalid DNS servers configured. Delete the one with bad data - this is an old method of defining resolvers that isn't used anymore but apparently has come to play here.

Something about the way MS Remote Desktop does DNS queries, it results in a more specific match against a different 'resolver' block here, which takes precedence over the current, learned DNS servers from DHCP. So, the DNS name resolves fine in terminal, other programs work, and you can use Remote Desktop with the target's IP address - but its DNS queries are falling into a black hole and it won't connect via name.

Running this command will give you a picture of all the DNS servers your system will try to use for different scenarios:

scutil --dns
Rusty Morgan 5 Reputation points

2024-09-19T13:00:13.5066667+00:00

Thanks for the comment and glad it solved your problem.

Turns out my problem was related to the upgrade to Sequoia. What was throwing me off is that it worked the day after the upgrade.

System Settings --> Privacy & Security --> Local Network

I had to turn that on for Remote Desktop and then mine was working properly. That doesn't explain how it worked the previous day though. I do remember seeing the popup about that at some point and I clicked no. Wish I could remember when I told it no as that would explain my issue.

Answer 2

Hyperion 15

Hi

thanks for your comment!

Reinstalling of the app didn't work.

But I found I can access the PC via its IP instead of the hostname.

So on mac I now can access the PC via IP addess.

iPhone and iPad can still acces per Remote Desktop app via the hostname.

Strange, but it works.

Greetings.

Brezinski Stefan 0 Reputation points

2024-03-13T19:37:19.0533333+00:00

Same problem here. Entered the IP where previously the hostname was set - solved it.

Answer 3

Hi all,
I do have the same problem since I upgraded from the Remote Desktop app to the new Windows App.

Interestingly, on my M1 MacBookPro it worked 100% seamlessly with the new app, but on my 2020 intel iMac 27" i7 it's broken since the upgrade.

I can, however enter the remote machine with the IP4 address instead of the computer name.

I tried to follow the steps of @Richard Hornbaker , but in the /etc/ folder on the iMac there is no folder called /resolvers/. Instead I found a file called "resolv.conf" containing two arbitrary (?) DNS entries that I cannot figure out. I do not know if this has anything to do with the case, but after deleting it, it is generated again automatically.

Answer 4

Jose Galvez 0

Microsoft Remote Desktop (previously), Windows app (now):

from your MacBook Pro (air) to your PC (you can work with your PC on your Mac) it works just fine,

from a PC to a Mac (I've never tried it),

from a Mac to another Mac it doesn't wor

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Answer 5

Anonymous

Hello,

If you can access via ip address, the issue is on your dns server, you dns server cannot recognize your Hostname (if your pc has no dns record in Operator network)

You can manually find the host file, then add your hostname and ip to the end of this file.

a. Type in ip

b. A "blank"

c. Type in hostname

If the Answer is helpful, please click "Accept Answer" and upvote it.

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Remote Desktop app on Mac not working anymore under macOS 14.2.1

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