After an update to the client, systems fail to shut down properly. If the client is removed, these systems shut down properly.
There is no error message, however, the PC shutdown does not complete successfully.
A file system deadlock with the Symantec AutoProtect component is responsible for this behavior. Two threads are waiting for exclusive accesss to a resource, and neither times out successfully.
This issue is resolved in the 22.9.3 release of Symantec Endpoint Protection Small Business Edition Cloud Antivirus Agent, available via new package deployments, and completing LiveUpdate deployment on 6/23/2017. See related articles for information on updating the agent using LiveUpdate on workstations or servers and checking the version.