When I want to open them for continuity, they report an error

When I save as a draft. When I want to open them for continuity, they report an error. It says "An unknown error has occurred. please ask your project leadership to email support@kobotoolbox.org with information about this form.

Attempt to invoke interface method ‘int.java.util.List.size()’ on a null object reference.

What can I do because sometime there is need to partial save and continue latter?

Welcome to the community, @briannasilele! Could you also let us know the mode of your data collection? Are you using the Collect Android App or are you using Enketo for this? Would also be easy for us if you share with us a screenshot of your issue. The screenshot would help us understand your issue pictorially.

That is the export error that shows
image

and am collecting data using Android App

@briannasilele, thank you for providing the details. We will get back to you as soon as we resolve this issue.