Error code 0x204 Remote Desktop Mac: how to fix the problem

This tutorial lists workarounds for error code 0x204 that may appear when a Mac user is trying to set up a Remote Desktop connection with a Windows PC.

Remote Desktop is an incredibly handy feature that allows users to stay agile in today’s multi-device and multi-tasking world. Developed by Microsoft, it bridges the gap between different operating systems by providing an easy way to access a Windows PC from another computer or mobile device that supports this technology. All it takes to establish a connection like that from a Mac is installing the Remote Desktop client, which is available on the official App Store by the way, and enabling the respective built-in functionality on the other side. This way, a Mac user can transfer files between their machines running different platforms and manage apps as well as settings as if the PC were in front of them. This is hugely convenient as long as it works as intended. Sometimes, the whole awesomeness goes down the drain due to Remote Desktop error code 0x204 on Mac.

When this issue kicks in, a user who is attempting to connect to a remote Windows machine may get the following alert:

“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”

The dialog doesn’t offer any troubleshooting mechanisms to get around the error, with the “Close” button being the only available option. As a result, reaching out to the remote host is a no-go, and the user is stuck with the annoying notification that won’t stop popping up whenever they try to connect. It's noteworthy that this drag mostly makes itself felt in a Mac to PC connection scenario rather than PC to PC.
The most common cause for the Mac error code 0x204 is a trivial one: the Remote Desktop feature is turned off in the PC computer the user is trying to reach. Obviously, this is a two-faceted procedure that requires full-blown support on either side. If one of the participating devices isn’t running Microsoft’s proprietary protocol, the attempt will fail.

A firewall solution, whether OS-native or third-party, is one more likely catalyst of the adverse situation. While protecting your machine against unauthorized incoming and outbound connections, it may block remote interoperability to help you err on the side of caution. This is understandable: the tool is simply doing its thing. Therefore, you may have to specify an exclusion to keep the firewall from red-lighting legitimate remote connections.

In some cases, antivirus software is to blame for this predicament, especially if it includes online security features such as network monitoring. The app may interpret attempts to set up a remote connection as a hacker’s foul play. If so, the Mac error code 0x204 Remote Desktop is imminent and you’ll need to tweak the program’s defenses so that it allows these connections through.

The top reason for this quandary on the Mac side comes down to redundant temporary data spawned by the RDP client. Purging the associated folder from the Group Containers directory usually addresses this issue in a snap. By and large, the root causes vary, and it takes a good deal of trial and error to figure out what exactly triggers the noxious notifications. The following guide will walk you through all the possible approaches to resolving the issue.

How to fix Remote Desktop error code 0x204 on Mac

This section will provide easy techniques to stop error code 0x204 from popping up on Mac when you are trying to establish a Remote Desktop connection with a PC.

Method 1. Make sure Remote Desktop is enabled on your PC

• Press the Windows+R keys simultaneously on the PC you are trying to connect to. This will open the Run box.
• Type SystemPropertiesRemote.exe and hit Enter.

• Click the Remote tab and ascertain that there is a checkmark next to “Allow Remote Assistance connections to this computer”.

• Click the Apply button to put the changes into effect and close the window.
• Check whether or not the error is appearing on your Mac. If it is, proceed to the following technique.

Method 2. Configure Windows Firewall to allow Remote Desktop connections

• Open the Run dialog on your PC again via the Windows+R key combination. Once it’s opened, type firewall.cpl as illustrated below and hit Enter.

• When the Windows Defender Firewall screen appears, click the sidebar entry that says “Allow an app or feature through Windows Defender Firewall”.

• In the “Allowed apps and features” column, find items named “Remote Assistance”, “Remote Desktop”, and “Remote Desktop (WebSocket)”. Make sure both the “Private” and “Public” boxes are checked next to each one.

• Click OK to save the changes and exit.
• Check if the error code 0x204 issue has been fixed. If it’s still there, use the tips below to give it another shot.

Method 3. Create a Windows Remote Assistance invitation

• Once again, use the Windows+R key combination on your PC to open the Run box. This time, type msra.exe and press Enter.

• When the Windows Remote Assistance screen shows up, select “Invite someone you trust to help you” as shown below.

• On the follow-up screen, click “Save this invitation as a file”.

• Specify the path to save the invitation and click the Save button.

• You will now get a unique password to establish a remote connection from another device.

• Use the password and the invitation file you have just saved to try and connect to the PC from your Mac. If the error code 0x204 isn’t popping up anymore, you are good to go. Otherwise, try the following technique.

Method 4. Turn off your antivirus protection temporarily

• If you are using a third-party antivirus tool on your Mac or Windows PC, it may prevent you from setting up remote connections, especially if it’s equipped with a firewall feature. Therefore, try to disable its protection modules and check whether the Remote Desktop error code 0x204 is still there.

Method 5. Remove Remote Desktop temp folder from your Mac

• On your Mac computer, click the Finder icon in the Dock, type “group containers” in the search bar (see screenshot below), and press Enter. Be sure to select “This Mac” rather than a specific directory in the search settings area.

• Spot the Group Containers folder in the search results and open it.

• Find the folder named UBF8T346G9.com.microsoft.rdc, right-click it, and select “Move to Trash” in the context menu.

• Restart your Mac and check if the Remote Desktop error code 0x204 problem has been sorted out.

Final thoughts

If none of the above has helped you address the issue, one more thing you can try is reinstall the Remote Desktop client on your Mac computer. In most cases, though, this isn’t necessary. All in all, the most challenging part about tackling the 0x204 error is that while it appears on a Mac, the reason is most likely on the PC side. So, give the above methods a go and hopefully you’ll be able to keep using the feature in a hassle-free way.