Thanks for your posting. The issue is likely that the fields were not really empty during the import (but had whitespaces, for example). TestRail’s UI ignores (trims) the whitespace characters and this explains the behavior you’ve seen after saving the test case in the UI. One solution is to make sure that the import files use empty XML elements for empty fields. You can alternatively also leave out empty fields and this would have the same effect.
I hope this helps!
Thanks for your reply but this is not the case.
I have check the value is empty without space.
When I click the edit button, there is empty in preconditions not even a space.
And also we import with empty value XML.
I also try to export the cases (some hide preconditions and some show preconditions without value)
to XML file and I got all of this cases with empty value in