System Workbench for STM32

Error with "sed"

Hi all,

since I am very new to the STM32 System Workbench I hope someone here can help me out.
I am currently trying to compile & program a STM32L152 board with the Contiki OS - which should be perfectly fine as there is an available port including examples. However whenever I try to compile one of those examples with the Workbench I get an error from sed: “/usr/bin/sed: -e expression #4, char 1: unknown command: `C’” - Unfortunately I was not able to find alot of information on that issue - please help.
OS: Windows 10 64bit with Cygwin installed
STM32 Workbench version: v.1.14.0
Board: STM32L152 Nucleo 64

Thank you all, greetings