Here's the reference,
Check this too might be of help
If you use NetScaler you will want to see these guides. The NetScaler How To Guides show administrators how to get NetScaler up and configured by providing instructions for common scenarios and some not so common ones.
This is an issue that we can get adding / removing permissions in the vCSA 6.0. We can also have issues searching for users / groups in the AD (using your identify sources). This is how one of the ways to handle this issues and fix it.