Hello,
Do you know how you set up the user authentication configurations in NetSight?
If you have it set up for LDAP, make sure your user account is not locked, or there is no problem with the LDAP services on AD.
You can also try to login with the root credentials. If you had configured the NetSight to fail back to OS credentials you might be able to get in that way.
If not you'll need to go into the mysql DB and enable fall back to OS.
Here's an article that will help with that:
https://gtacknowledge.extremenetworks.com/articles/Solution/Unable-to-login-to-Netsight-Console-usin...
Thanks
-Ryan