Try entering the password again. Be sure that the Caps Lock key on your keyboard is turned off and there are no typos.
If you have not changed your password, be sure it is entered exactly as the financial institution sent it to you.
Capital letters, spaces, dashes, periods, and other symbols should be used where needed (and only where needed), with no extra ones.
Check that the password is for this account at the financial institution, not something else.
For example, you usually need different logon information for QuickBooks than for the financial institution's Web site.
Contact your financial institution to confirm that your online service is active.