Become superuser or assume an equivalent role.
Roles contain authorizations and privileged commands. For more information about roles, see Configuring RBAC (Task Map) in System Administration Guide: Security Services.
Change to the /var/adm directory.
Convert the wtmpx file from binary format to ASCII format.
# /usr/lib/acct/fwtmp < wtmpx > wtmpx.ascii
Edit the wtmpx.ascii file to delete the corrupted records.
# /usr/lib/acct/fwtmp -ic < wtmpx.ascii > wtmpx
See the fwtmp(1M) man page for more information.