"invalid 'nsmall' argument" error shows up if I enter a larger value or negative value for "Number of Decimal Digits" setting in Chart

You may see the error like the following if you enter a larger value or negative value for “Number of Decimal Digits” setting in Chart.

Error: Error in prettyNum(.Internal(format(x, trim, digits, nsmall, width, 3L,  : 
  invalid 'nsmall' argument

You can try setting a smaller, positive integer value to fix the issue.