Here in this article, I will share the details for the Rainbow Six Siege error code 0-0x00000300.
The error reads, “An error has occurred.”
As per my research, the error comes when players try to launch the game, and the error is not limited to any specific platforms and may come despite what platform you are using to play R6.
My research also suggests that this error is coming because of an outdated game version, or there is a bug in the game.

Fixes For Rainbow Six Siege Error Code 0-0x00000300
Fix 1: Do A System Restart, And Check For Update
My first suggestion for you will be to perform a system restart.
Simply shut down your gaming device along with the internet, and let them rest for around ten minutes. Then restart your device and check if the error persists.
If the error persists, check if there is a pending update for the game, if so then consider updating the game and check for the error again.
Fix 2: Disconnect And Reconnect To The Internet
As a next troubleshoot, disconnect your device from the internet and wait for around ten to twenty seconds. Then reconnect your device to the internet, and check if now you can see any update for the R6.
During my research, there were a few players who were getting this error and the game was showing up to date, but when they disconnected and reconnected the internet to their device, the game started to show a pending update, and as they updated the game the error got resolved. So I suggest you do the same for you.
Fix 3: Try Verifying The Integrity Of The Game File
If you are playing on Steam then try Verifying the Integrity of game files.
Many Steam players have shared that verifying the Integrity of the game helped them fix this issue, so if you are also on Steam then try doing the same and check if this helps.
Here is how to Verify The Integrity Of The Game File.
- Close the Steam.
- Restart your device.
- Launch Steam.
- Tap on the library from the top of the screen.
- Go to your Game and Right-click on it, or tap on the Gear icon.
- Select Properties.
- Select the Installed Files tab.
- Select Verify integrity of game files.
Fix 4: Check Update For Graphics Drivers
Next, I advise you to check and ensure that your Windows PC graphics drivers are up to date, if not then I advise you to update them and then check for the error again.
Fix 5: Check If Your Antivirus/Firewall Is Blocking The Game
If the error still continues then check if the issue is your Antivirus/Firewall.
You need to simply disable your Windows PC Antivirus/Firewall, and then check if the error continues.
If this resolves the issue then this means that your Antivirus/Firewall is conflicting with the game and as a result, this error is coming. So to resolve the issue you have to add Rainbow Six Siege to your Antivirus/Firewall exception list.
Fix 6: Try Reinstalling The Rainbow Six Siege
If all the suggestions given above fail to resolve the issue then I advise you to wait for a couple of hours and try playing again. This way you can confirm if the issue is caused by game servers.
In case the error is not going away even after waiting for several hours then you should consider reinstalling the Rainbow Six Siege on your device.
If you need help with reinstalling Rainbow Six Siege on your device then depending upon your platform you can pick from the below given guides.