Users are unable to manage partitions on external drives with the 11.1.0 Drive Encryption Client installed. This includes formatting or resizing, adding, and deleting partitions on external drives.
In the Windows Event Viewer:
Event 3162 - "Applications not allowed to partition disk after DE installation"
Managing partitions on Internal/Managed disks is not allowed when the Drive Encryption client is installed. In version 11.1.0 this also affected External Drives.
This issue is fixed in the following release:
This version of Endpoint Encrypton is available for download via your account on Symantec File Connect. https://fileconnect.symantec.com