Here is an example of an error that happens when a field has got a value of NaN.
This error relates to a Field that has got a value of NaN (Not a Number). This is caused by an expression that can result in a divide by zero. By exporting all the data to .csv and checking for values of NaN this is present in the following Fields. These will need the expressions updated to account for the divide by zero case. I have added examples for these but any expression that could have a 0 denominator will need to be updated as well to avoid the divide by 0 case using an if statement to catch it from resulting in NaN.
See example here of the export CSV document where you can see the error on the data.
You will need to update the field as per below:
Field to update --? HazardousEnergyScore
([HazardousEnergyPoints] / [HazardousEnergyPointsPossible]) *100 --> if([HazardousEnergyPointsPossible] = 0, 0, ([HazardousEnergyPoints] / [HazardousEnergyPointsPossible]) * 100)
Once updated, importing to change the value of HazardousEnergyPoints or HazardousEnergyPointsPossible will rerun these expressions and set the values for the Fields back to Numbers.