If your active program window crashes suddenly or
your system starts freezing for a few seconds at a time, it means the error 521
has occurred. If you want to fix this error, you will have to follow the troubleshooting
steps mentioned below, and it will help you get rid of the problem
Steps you have to follow:
1) Check
your PC driver
2) Remove
the junk files
3) Complete
Virus scan needs to be done
4) Check
registry entries
5) Undo
recent system changes
6) Reinstall
AIM program
7) Update
the window
8) Use
Windows system file checker
9) Clean
installation of Windows
These are the troubleshooting methods that you can
use to fix AOL mail error 521. These methods are surely going to help you. But
if these steps don’t come out to be helpful, you can contact AOL Tech Support to get
assistance from technical experts who will extensively guide you.
Solved: HOW TO FIX AOL MAIL ERROR 521