System Workbench for STM32

Hi All,

I'm new in this area and have a small but for me very big problem. I can't Run/Debug my project using Workbench. At trying to do it the tool returns following Error message:

" OpenOCD child process termination

Reason:
Unplugged target or STlink already in use or STlink USB driver not installed"

Need to mention that my target is plugged and I can program and debug it by using Keil uVision.

Could you please help me to solve this issue?

Thanks In Advance,
Hayk