# Webforms behaviour notes

**URL:** <https://forum.getodk.org/t/webforms-behaviour-notes/58272>\
**Category:** Support\
**Tags:** odk-webforms\
**Created:** [June 16, 2026, 5:47am UTC](https://forum.getodk.org/t/webforms-behaviour-notes/58272 "2026-06-16T05:47:32Z")\
**Posts on this page:** 1\
**Showing post:** 35

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**Author:** ![ahblake](https://getodk.b-cdn.net/user_avatar/forum.getodk.org/ahblake/32/22392_2.png) [@ahblake](https://forum.getodk.org/u/ahblake)\
**Post date:** [August 20, 2026, 1:01am UTC](https://forum.getodk.org/t/webforms-behaviour-notes/58272/35 "2026-08-20T01:01:30Z")

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@JenniferQ / @gareth

I have a form that I went to switch from Enketo to WF and on load received the following error

> An error occurred while loading this form  
> The function 'distance' received a value that does not represent GPS coordinates

The field with the function had a calculation as  
`round(distance(${line_trace}),2)`

Adding a trigger to the field as `${line_trace}` allowed the form to load, but I guess it would be preferable if the form didn't fail on load if distance evaluates on a blank field. Not sure if this is already resolved with other changes for v1.0.3

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