Errors Which Are Displayed for Formulas
There are two types of formula errors. One is the error displayed when you set a formula and the other is the error displayed when you enter records.
Errors Displayed When Setting a Formula
The following section describes the errors you might get when you enter and save a formula on the App Settings page.
Error  Cause and Solution 

You have entered a fullwidth symbol "XX". Use a halfwidth symbol "XX" or check that the entered value is correct.  This error is displayed on the formula setting screen when you entered a fullwidth symbol wrongly, instead of a halfwidth symbol. For example, this error is displayed in the following formula because it contains a fullwidth quotation mark (”). Example: IF=(Option=” On the other hand, this error is not displayed in the following cases.

The field code in the formula does not exist or has invalid format.  This error is displayed in the following cases:

Field references cause an endless loop.  This error is displayed when you specify the Calculated field as a formula for the Calculated field. This error is also displayed when referring the Calculated field B from the Calculated field A, or when referring the Calculated field A from the Calculated field B. 
Function x requires y arguments.  This error is displayed when the number of arguments specified for the YEN/DATE_FORMAT/NOT/IF/CONTAINS function is not enough. 
Function x requires y or more arguments.  This error is displayed when the number of arguments specified for the AND/OR/SUM function is not enough. 
Function ROUND (or ROUNDUP/ROUNDDOWN) requires 1 or 2 arguments.  This error is displayed when the number of arguments specified for the ROUND/ROUNDUP/ROUNDDOWN function is not enough. 
Function x does not exist.  This error is displayed when you specified a function which cannot be used in Kintone. 
Function x accepts up to y arguments.  This error is displayed when you specified more than acceptable number of arguments for the formula for the Calculated field or the Text field. 
Invalid formula format. 
This error is displayed when the formula cannot be solved. For example:

Relevant function is not used for the value of the array type. As for values of array types and their usage, refer to the help.  This error is displayed when a formula refers to the Check box/Multichoice field, or a field in a table is referred outside from the table. In both cases, a formula refers to an "array type field". To refer to the Check box/Multichoice field from a formula, or to refer to a text type field (Text, Radio button, Dropdown, or Lookup whose source is Text) in a table outside from the table, use the CONTAINS function. Note that a formula which resides outside of a table cannot refer to the Check box/Multichoice field in the table. To refer to a numeric type field (Calculated field, Number field, or Lookup whose source is Number) in a table outside from the table, use the SUM function. For using SUM and CONTAINS functions, refer to the following pages: CONTAINS Function: Calculation using Check Boxes and MultiChoices SUM/CONTAINS Functions: Calculations in Tables 
Errors Displayed When Entering Records
This section explains errors that are displayed in the field where a formula is set, when entering records.
Error  Description 

#CONVERT!  The value cannot be converted. This error is displayed when the calculated result in the calculated field is a string. The result value in the calculated field should be either number, date and time, date, time or hour. Use the Text field if the result value becomes a string. For more details, refer to the following page. When the Calculated Result in the Calculated Field Is a String (Cause and Solution for #CONVERT! error) 
#PRECISION!  The result value exceeds the number of significant digits. For details on how to set the significant digits, see the following page: Setting the Significant Digits of Numbers and the Rounding Method 
#VALUE!  This error is displayed when the value type or the operator is not appropriate. Example 1: Adding a string to a value Example 2: Using the + operator for concatenating strings For example, any number you entered in a dropdown is treated as a string. It cannot be used for calculation as a number. Refer to Data Types of Values Referenced by Formulas 
#ERROR! (Not for DATE_FORMAT function)  The calculation cannot be performed. For example, when dividing a number by zero (0), exponent exceeds 100 or falls below 100, etc. 
#ERROR! (For DATE_FORMAT function)  This error is displayed in the following cases:

When the Calculated Result in the Calculated Field Is a String (Cause and Solution for #CONVERT! error)
If you set a formula in the Calculated field when the calculated result is a string, #CONVERT! error is displayed.
In this case, calculated result can be displayed by using the Text field. Select "Calculate automatically" in the Text settings screen, and then enter a formula.
Now, the calculated result "Clear" is displayed.