When I try to sign into Yahoo Messenger 9.0 I get this error message "Messenger encountered a connection problem. Please check the network connection and then click try again. (81003004)" I've changed my proxy settings and all that and it still won't work. How can I fix this?

You might have some options to fix it: firstly; this error occurs when your connection preferences are not properly set. I'm not talking about your Yahoo! ID and Password here, but you may need to adjust certain features depending on what network you're on. Maybe, i think you should check your firewall settings. If you use Personal Firewall, make sure it allows your connection to receiving incoming connections and allows you to use yahoo messenger,check it out, may be it blocked your yahoo messenger. if a firewall protects your network, it may block yahoo messenger when it tries to connect to the server. You need to change your connection settings, click the Messenger menu in yahoo messenger and select Connection Preferences. Select Firewall With No Proxies. Select your Internet Connection type from the pull-down menu at the bottom and enter your Home Country if the adoptions aren’t grayed out. Click OK and login again using the new settings. If this option doesn’t work, click Connection Preferences in Yahoo! Messenger again and select No Network Detection. Try to login again using the new settings. In some instances, you may need to provide yahoo messenger with the IP address of your firewall or proxy server (you can get this information from your network administrator or from your Internet service provider). Click Messenger and select Connection Preferences again. Select Use Proxies. Enable either the HTTP Proxy or the SOCKS Proxy as needed and provide the proper address. Click OK and login again using the new settings.

Or other way, open your Internet Explorer>Go to File>Then, 'uncheck Work Offline', make sure your Internet connection is not working offline. Then, close Internet Explorer, try to sign in your yahoo messenger.

thirdly, if you are using IM9 there are sign in problems. This is what yahoo has to say. Try an updated version of Yahoo! Messenger 9.0(9.0.0.2128). This latest build includes a fix for the sign-in issues that have been affecting some users. If you were seeing an error code“81003004” when trying to sign in, this latest version may fix that problem. Even if you were experiencing a different kind of sign-in issue, I recommend installing this latest version. Hope it was helpful and it works to solve your problems.. Please kindly support me.. Thank You!