Applies to:
Oracle Server - Enterprise Edition - Version: 9.2.0.8 and later [Release: 9.2 and later ]
Information in this document applies to any platform.
Kewastunpackstats(): Bad Magic 1 (0x1108f7b87, 0) in Alert Logfile After Upgrading to 11.2.0.1

Symptoms
The following message is reported in the instance alert file:

kewastUnPackStats(): bad magic 1 (0x1108f7b87, 0)

Cause
The cause of this problem has been identified in Bug:8967729 which has been closed 
as duplicate of unpublished bug 8730312.It is caused by the variable part of 
the Active Session History rows (the moduile, action program, etc. information) 
not being stored properly, causing any read-back of this data through views like 
(G)V$ACTIVE_SESSION_HISTORY to fail.

Solution
The issue has been fixed in the upcoming Oracle12c release and the 11.2.0.2 and higher patchsets. 
The solution is to install the 11.2.0.3 patchset 
(which is the current patchset at time of publishing this Note (MAR-2012).

Apply Patch:8730312 for any other environments.
As one-off patches are not subjected to the same rigorous level of testing as done 
for Oracle Server patch sets, you are encouraged to install and test this patch 
in a test environment prior to full production implementation.