Red Alert 3 Online (CA public key / Debugger / Failed Connection Errors Solved)

This 2020 blog post tells you how to play Red Alert 3 online.

Warning: You take responsibility for any problems arising from files you download. I don’t recommend you uninstall a firewall.

Red Alert 3 game lobby

My fiancée and I decided to play Red Alert 3 online together. We usually play the LAN version, but the co-op version of the campaign levels are only available online. The problem is that EA shut down their RA3 servers! Thankfully at the time of writing you can do so for free via C&C:Online.

The installation went smoothly on a PC, but on the second PC I ran into trouble. This blog post goes into detail what I did to, so that my fiancée and I could play the campaign co-op maps together.

How to play RA3 online:

  1. Register with
  2. Log-in to and then create a server account.
  3. Download the C&C:Online Launcher.
  4. Run the launcher, then select ‘Red Alert 3’.
  5. When wishing to play online multiplayer, log-in using the server account (instead of using EA details) that you created in step 2. *
  • When you create a server account, you create a name and password. When entering into Red Alert 3, I typed in the email address used when I registered at CNC-Online.

C&C:Online Launcher application

Where you type log in details for Red Alert 3

You can either choose to play a co-op campaign game or just online play against others. If you wish to play ‘online’ with or against somebody on the same LAN (but don’t wish to play a LAN game), please read the ‘Failed connection’ section further down.

C&C:Online Setup – Could not write value Debugger to key error
I ran into the debugger error message and it occurred even when I was logged into an administrator account on Windows 10.

Could not write value Debugger to key

I am using ZoneAlarm Free Firewall on the PC with Red Alert 3 installed. I tried to configure and then ‘snoozing’ the firewall for five minutes, but that didn’t solve the problem for me.

Then I uninstalled ZoneAlarm Free Firewall and the C&C:Online setup application installed without the ‘Debugger’ problem. Immediately after I closed the setup application, I reinstalled ZoneAlarm Free Firewall. I am not suggesting you uninstall a firewall, but just writing about what I did! 

Error: CA public key patching routine failed
The next problem (on the same PC!) was that I couldn’t get the C&C:Online Launcher to run Red Alert 3 without showing an error.

C&C:Online error message

How to resolve the CA public key patching error:

  1. Run the C&C:Online application.
  2. Select ‘Red Alert 3’ from the ‘Hook’ menu.
  3. Close the C&C:Online application.
  4. Run RA3 via the Start menu.
  5. When the C&C:Online application opens, select ‘Red Alert 3’.

Now in the future, all you should need to do is go through steps 4 & 5 above to play the game.

Screenshot of the C&C:Online Launcher application

Failed connection:1-2 error
So at this stage, I’ve thought everything is finally working. We’ve signed in to the server and as we’re about to play the game, we see the failed message.

An edited Red Alert 3 screenshot

This time, the issue is because we’re using the same connection. On one of the PCs I ran a VPN connection (using a free Windscribe account) and finally my fiancée and I were able to play the online campaign co-op levels together.

I’ve purposely been trying to reduce my outgoings on games this year. I’ve enjoyed being able to experience a game I’ve owned for many years in a new way. Well done and thank you C&C:Online.

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