ORA-28056: Writing audit records to Windows Event Log failed

This Problem occurs when we are trying to connect as sysdba. This error may occur at anytime when there Event Viewer log become full. In my case it occurs when connecting with sys user as sysdba privilage  and once while creating the database(through dbca when it has completed 85% ).

C:\> sqlplus sys/xxxx@noida as sysdba

ORA-28056: Writing audit records to Windows Event Log failed.

Cause of the Problem : The problem happened because Event Viewer log is full and not able to log anymore events.

Solution of the Problem :  This was because the Event Viewer log is full and could not log anymore events.

The solution is to clear the event log .To solve this issue follow any of the following steps.

1) When a log is full, it stops recording new events. Clearing the log is one way to free the log and start recording new events. To do so, on the Action menu (left click)or on the left side Application/System/Security (as available) right click and select Clear All events.

2) We can also free a log and start recording new events by overwriting old events. To overwrite events, on the Action menu, or on the left side Application/System/Security (as available) click Properties, and then click Overwrite events as needed. This ensures that all new events are written to the log, even when the log is full. 

3) We can also start logging new events by increasing the maximum log size. To increase the log size, on the Action menu or on the left side Application/System/Security (as available) click Properties, and then increase the Maximum log size by typing a bigger value.

Enjoy  :-)