Unable to copy because of dependency in parent, child, or sibling site

Symptoms

When attempting to copy a site object, ShareGate Migrate displays one the following messages:

Unable to copy this site object because it has a dependency located in a site that is not part of the parent hierarchy.
The lookup column cannot be copied because the list 'My List' is not in a parent site or in the same site as the column.
A control in this Nintex form depends on a SharePoint site that is a child or a sibling of the source site.

Error code

Details

This error happens when copying a site object that has a dependency that is not located in the parent hierarchy, but rather in a sibling or child site. For example, given the following site hierarchy: 

The source site  project-a has custom list with a lookup that refers to a list located in the sibling site project-b. In this context, ShareGate Migrate will display an error when attempting to copy the custom list somewhere else, because it can only resolve dependencies that are within the source site, or one of its parents.

Solution

There are three possible solutions to this issue:

1. Move the dependency in the source site or one of its parent, as depicted in the following image

   

2. Remove the lookup column with the dependency from your custom list, copy the custom list to its destination and then manually recreate the column and its dependency.
3. Update the Nintex form at destination after copying the site on which it depends or move the referenced list into the source site, update the source Nintex Form to reference that list and restart the migration.