Problem Solved
To solve it I went to:
Run => Debug Configurations => Ac6 STM32 Debugging (navigator on left)
I clicked on the “New launch configuration” icon to the upper left. Under navigator item “Ac6 STM32 Debugging” a new launch configuration item appeared. I clicked on this item to select it. In the panel to the right I entered a new lanuch configuration name in the “Name” field located across the top.
For:
Main (tab) => Project (field)
I clicked on the “Browse” button and selected the project name. Once this was done the elf file path and file name (relative to the Eclipse project) appeared in the “C/C++ Application” field.
For:
Debugger (tab) => Script (group)
I selected the “Manual spec” radio button. Two fields, a “Debug device” field, and a “Debug interface” field appeared. In the “Debug device” field I selected the emulator probe I am using (ST LinkV2). In the “Debug interface” field I selected the interface the board has connections for (JTAG).
I am now able to launch a debug session.