Try the below steps and let us know if you are able to start the server successfully.
1.- Restore the cwallet.sso from a backup (recommended),
2.- copy cwallet.sso file inside "<FMW_DOMAIN_HOME>/config/fmwconfig" directory to ""<FMW_DOMAIN_HOME>/config/fmwconfig/bootstrap" directory and restart the server instance,
3.- Delete the corrupted cwallet.sso file and restart WLS admin server.
Note. If the issue still persists, turn on the debug flag -Djava.security.debug=jpspolicy and reply back with the logs which has debug traces.