If you are trying to Add or Multiple fields together, you need to use the SUM or PRODUCT Functions in Forms 10 or you will see errors such as this when a field is empty. Reference errors can be a result of not being able to find the variable, improper bracketing or formula structure.

Can you provide your formula here so that we can tell what part cause error? What field type of the two referenced field and what value of them when you get the calculation error?

It's not an error. I am asking for specifically for the function definition as it is unpublished from what I can tell.

The SUB function is to do subtraction between two numbers. In 10.0, if you use two currency fields as parameters for this function, then it will show "The field contains a calculation error" when one of the field is blank, no such error when use two number fields as parameters. This issue has been fixed in 10.1 for 10.1 will treat empty value as 0 for operators.

I'm still running into this issue. I am running 10.1.0.642.

Here is a picture of my table

Here is a snap of my formula:

=SUB(INDEX(TRAVEL.Total_Expense_2,ROW()),INDEX(TRAVEL.GST_HST_2,ROW()))

Here is a snap of my error when 1 field is blank:

I just attempted to get two currency fields to subtract from each other using the SUB option and kept getting the same error.  I ended up having to use SUM but multiply the 2nd value by -1 to get it to work as subtraction.

•  =SUM(Currency1,PRODUCT(Currency2,-1))

Also, if SUB is something we can use, why isn't it in the help files?  Sure would be nice to see it in https://www.laserfiche.com/support/webhelp/Laserfiche/10/en-US/administration/#../Subsystems/Forms/Content/FieldCalculations.htm along with anything else (like if there is a division option DIV?).