Possibly Bug.. Need help

Hi,

could anyone help me with this! … in sales order doctype multiple ‘cost center’ entries are there. I tried to delete one entry from the list and try to update the doctype. but it’s not allowing me to update it. below is the screenshots for both… anyone have any idea?
.
.

After deleting try refreshing the page using Ctrl+Shift+R keys combination and then try again.
Or else try using ‘Edit Doctype’ rather than ‘Customize form’

@murtaza_bk

I tried all that… even OS rebooted… only one thing left now… manually deleting the entry from the database… before that I wanted to ask if there is any solution to clear it. why that happened in the first place… thank you so much for the reply anyway…