Krithik,
I think you may have missed out the step 3.3 in lab 5:
Remove Task service if it exists in your .cfg file.
In the empty example, a heartBeatFxn task is created in the .cfg file. This has be removed from your .cfg file.
Also, you can check out the solutions and compare them with your labs. They are in the path <install_dir>/TI_RTOS_labs_sols_rev2.10/TM4C/Sols.
Vikram