can't create new partition on healthy SSD

I cannot create a new partition on a healthy SSD. In Disk Management, when trying to shrink the existing, healthy partition to create unallocated space for the new partition, I receive the Virtual Disk Manager error message, "The service cannot be started, either because it is disabled, or because it has no enabled devices associated with it." (No error message number.) The SSD is a Samsung 840 512GB installed to three volumes with Samsung's supplied software under Windows 8 on a new Lenovo T530. The partition I want to shrink is 475GB with plenty of unused space. In setting up the SSD with Samsung's SSD Magician, the only system changes I made were to disable defrag and disable most indexing, and I did not disable "superfetch" (if that's relevant).