Related items not displaying in dialog New form

[Oz.Ab]

Hi guys.

I have a 'Parent Edit Form' that opens in regular mode.
When I want to add a child item I click the '+New item' button and the child form opens in dialog but the related items is not showing (Unable to display this Web Part. To troubleshoot ...).
This 'Child New form' only has:
- 2 text fields
- 1 related items

If I open the 'Child New form' in regular mode (not dialog) then the related items displays correctly.

I have searched the forum from A-Z but I can't find anything about this.
I have already stripped the form and only inserted the related items but it still does not work in dialog.

Please assist - I just don't understand this problem.

[Nikita Kurguzov]

Dear Oz,
Does the parent form have RootFolder parameter in its URL? It can be causing it. If it does have RootFolder, try to remove it from URL and reload the page, see if Related Items will show up or not.

[Oz.Ab]

Thanks - problem solved