ORA-28056: Writing audit records to Windows Event Log failed Error
Today I got ORA-28056 error when trying to connect to Oracle Database 11g Enterprise Edition Release 126.96.36.199.0 running on Microsoft Windows XP.
SQL> conn /as sysdba;
ORA-28056: Writing audit records to Windows Event Log failed
ORA-01031: insufficient privileges
This was because the Event Viewer log is full and could not log anymore events.
The solution is to clear the event log as follows Control Panel->Administrative Tools->Event Viewer->Clear All Events
If needed you can backup the existing logs before clearing them and eventually increase the log size.