Known issues with Ensemble Studios Online when you play a multiplayer game of Age of Empires III

Issue 1: CRC Mismatch error message

When you try to start a multiplayer game of Microsoft Age of Empires III, you may notice that the ESO game browser includes the name "CRC Mismatch." If you click to join one of these games, you receive the following error message:

This issue may occur for one of the following reasons:

• Another person with whom you are trying to play has different expansion packs installed.

• Another person with whom you are trying to play has different software updates installed.

• Another person with whom you are trying to play has different modification (mods) installed.

• You are running an unsupported version of the game, and the game executable was modified.

If you already running the latest game updates, and if you have the same expansion packs installed as another player with whom you are trying to play, remove and then reinstall the game to resolve this issue. If you do not have expansion packs installed, you have to purchase them or join another game. If you do not have the latest game updates, see the "Game Updates" section in this article.

If you do not have certain third-party mods, either download them or try to join another game that does not require third-party mods. If you have installed a third-party mod, and if you are unaware of which files that the modification changed, remove and then reinstall the game. Then, apply the latest game updates.

If you have installed any hacking utilities or patches, remove and then reinstall the game. Then, apply the latest game update.

Issue 2: Failure to connect to the ESO server

When you try to connect to ESO, you may receive the following error message:

This issue may occur if you have an antivirus or firewall program running on the computer. For example, if you are using firewall software such as Zone Alarm, MacAfee Personal Firewall, Norton Internet Security, or Black Ice Defender that allows for or blocks access to the Internet on a per-program basis.

To resolve this issue, disable your antivirus or firewall software. You can contact the program manufacturer to help you disable the program. Some of these programs you can see on the lower-right corner by the clock. You may be able to disable it. To do this, right-click the program, and then click Disable or click Exit. If the issue continues to occur, perform a clean boot procedure.

For more information about how to perform a clean boot procedure, click the following article number to view the article in the Microsoft Knowledge Base:

331796 How to perform a clean boot procedure to determine whether background programs are interfering with a game or a program that you currently use

Issue 3: Lost connection to ESO

The ESO servers may be temporarily down or under maintenance. If you cannot establish contact with the server, and if you have tried all other methods to reestablish the connection, you may have to wait until the servers are brought back on line. Please wait for 30 minutes, and then try to connect again. Continue to try to connect until the servers are running again and the issue is resolved.

The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, about the performance or reliability of these products.