From what it seems, this error is caused either by your Windows Firewall or security program which doesn't allow the client to connect to the main server. In order to fix it, check your antivirus settings. After that, go to Start > Control Panel > System and Security > Windows Firewall > Allow a program through Windows Firewall and check the box next to Wizard101. If you can't find the game in the Allowed programs and features window, press the Allow another program button, navigate to the installation directory, select the executable file and press Add. Also, from the Advanced Settings select Inbound Rules > New Rule. Check the Port box, click Next, select All local Ports and follow the self-explained steps. If it doesn't help, it's possible that some of the game's files to be corrupted. In this case, I suggest you uninstall it and download and install the latest version of the client. If the problem persists, you can get in touch with the Support Team using
firstname.lastname@example.org email address.