[Discuss-gnuradio] error list terminal window

while running "simulator_cw.grc"I got error messages like this in terminal window

 Loading: "/home/vinay/gr-radar/examples/simulation/simulator_cw.grc"
>>> Error: Block key "radar_signal_generator_cw_c" not found in Platform - grc(GNU Radio Companion)
>>> Error: Block key "radar_qtgui_scatter_plot" not found in Platform - grc(GNU Radio Companion)
>>> Error: Block key "radar_qtgui_time_plot" not found in Platform - grc(GNU Radio Companion)
>>> Error: Block key "radar_estimator_cw" not found in Platform - grc(GNU Radio Companion)
>>> Error: Block key "radar_ts_fft_cc" not found in Platform - grc(GNU Radio Companion)
>>> Error: Block key "radar_os_cfar_c" not found in Platform - grc(GNU Radio Companion)
>>> Error: Block key "radar_print_results" not found in Platform - grc(GNU Radio Companion)
>>> Error: Block key "radar_print_results" not found in Platform - grc(GNU Radio Companion)
>>> Error: Block key "radar_static_target_simulator_cc" not found in Platform - grc(GNU Radio Companion)
>>> Done
 

can some one please inform me cause for this

-vinay