Argument(s) Error... Illegal file format for composite patch.

While installing 11.2.0.3.8 composite PSU, I was getting following errors:

[oracle@ora-test-1 16902043]$ opatch apply
Oracle Interim Patch Installer version 11.2.0.3.0
Copyright (c) 2012, Oracle Corporation.  All rights reserved.

Argument(s) Error... Illegal file format for composite patch. There is no composite.xml file. Either this composite patch is not packaged properly, or you are applying a constituent individually.

Please check the arguments and try again.

OPatch failed with error code 135

Reason:

Patch apply was executed when current working directory was  "/16902043/16902043"

Solution:

We should be one directory level up while applying the patch:

cd /16902043

we need to execute "opatch apply" under //16902043 not under //16902043/16902043