Default value to null

Hi !
I've this problem. The form includes a set of mandatory integer questions, which by default are set in 0 and have the constraint of .>=0. It appears, that once we import the file to Excel (65001: Unicode (UTF-8) some of the fields show a null instead. This error has an effect on the calculated fields associated with and thus bring error as well.

Beneath two screenshots:

I see the tomcat logs and MySQL and I don't see any error . I guess the problem will be in odk collect but i'm no sure

What app or server are you using and on what device and operating system? Include version numbers.
ODK Aggregate v1.7

Hi @sowe1

as a work around, are you not in a position to recode null to 0 in your statistical analysis application and recalculate calculated fileds in the statistical application?