System crash when execute "app_timer_start" in nRF52832

Hi,

I am using SDK15.2 to develop my project.

When I execute "app_timer_start" function (At line 115 of  main.c), the system will crash.

Please reference the attach file for the attach file.

TimerTest.7z

Would you please tell me how can i solve this problem?

Thank you,

Chianglin