Do you use AOL messenger app? Have you been facing AOL server error 400 whenever you try to reinstall or update the software? Relax! The issue is quite common and fixable. You can fix it on your own by following some simple troubleshooting steps such as running the Antivirus program, or you can uninstall the software and then install it again. But if you want an immediate solution, you can get in touch with AOL technical support number . The experts provide you with the most prominent solution in no time at all. The best part is that these professionals are available 24/7 to serve you with the best results.