Run error on merge sort

can you please check what is wrong in the implementation why I am mistaking, again and again, the output gives as run error

I hope I’ve cleared your doubt. I ask you to please rate your experience here
Your feedback is very important. It helps us improve our platform and hence provide you
the learning experience you deserve.

On the off chance, you still have some questions or not find the answers satisfactory, you may reopen
the doubt.