Knowledge Base/League of Legends Player Support/Technical Support

Connection Failure Error

posted this on August 09, 2010 16:49

Last updated: 4/4/2013

Occasionally, users experience issues when trying to log into the client. If you are having this issue, it is most likely due to either a firewall that is blocking a connection to our log-in server, or because League of Legends has not properly been added to your exceptions list.

Connection Failure: Unable to connect to the server

Symptoms of Connection Failure


Before reviewing this article, please confirm there are no known issues with our login process by checking the server status forums:


Sync the Clock in Windows

Syncing your clock will enable us to authenticate with your system and log-in servers.

  1. Press [Windows Key] + R
  2. Type cmd
  3. Press "Ok"


  1. Type net start w32time
    This will start the time sync service if it is currently not active 
  2. Press Enter
  3. Type w32tm /resync
    This will resync your clock. If it fails you may manually have to set your time AND date. 
  4. Press Enter


If you encounter any problems with this process, more in-depth instructions can be found in the following article: Syncing Windows Clock

Update Windows

Make sure you have all available windows updates installed from this website:

Check your Firewall Settings

Try each of the possible solutions listed below. If you are having trouble with these steps, our support staff is more than happy to help you to the best of our abilities, but please note that your firewall's manufacturer is likely to be more knowledgeable about the configuration of their software. 

Potential Firewall Solutions: 

  • Disable Windows Firewall and see if this clears up the issue. 
  • Disable any third party firewalls and anti-virus software. (Examples: Norton, McAffee, AVG)
  • Make sure that Port 2099 is open
  • Make sure that LolClient.exe has been added to your firewall exceptions list.

This information may be helpful in configuring your exceptions:

  • North America Login
    Server IP:
  • Europe West Login
  • Europe Nordic & East Login
    Server IP:

For more in-depth instructions for properly configuring your Firewall, please refer to the following article: Firewall Configuration for League of Legends

Check Your Network Connection Settings

Even if everything else on your network seems to be working perfectly, there are many settings that could specifically cause issues with League of Legends. Please refer to the following article for the best troubleshooting steps for these issues: Improving Lag, Latency and Ping

If you continue to have problems with connection failures please send in a ticket to our Technical Support Team.

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