On_update function not working

ERPNext
1

I updated my ERPNext to version 8.5.4.

After the update, I wrote frappe.errprint("Hi") in the on_update function of the Sales Invoice. But, when I save a Sales Invoice, I do not see ‘Hi’ in the console. Anything I write in the on_update function is not happening.

Please help ASAP.

2

Share your code / script.

3 
def on_update(self):
    frappe.errprint("hi")
    self.set_paid_amount()

I just added the second line.

4

Are you on develop or production mode? In production you have to restart supervisor everytime you make a change.

5

I am on production mode.