We accidentally created the forms folder at parent Location 2 and want to move it to parent Location 1 via Public API

$this->repo->sudo(
    function (Repository $repo) {
        $locSvc = $repo->getLocationService();
        $form = $locSvc->loadLocation(58);
        $parent = $locSvc->loadLocation(1);
        $repo->getLocationService()->moveSubtree($form, $parent);
    }
); 

But then get an error

Type error: Return value of eZ\Publish\Core\Repository\Values\Content\Conte  
  nt::getContentType() must be an instance of eZ\Publish\API\Repository\Value  
  s\ContentType\ContentType, null returned 

This is because the special location 1 has no content (id 0) although it has a content-type 1 (folder).

The check in vendor/ezsystems/ezpublish-kernel/eZ/Publish/Core/Repository/LocationService.php Line 675 is the cause, because it tries to fetch the content-type from the content instead of the location.

if (!$newParentLocation->getContent()->getContentType()->isContainer) 

Solution: Fetch the contentType via the contentTypeId attached to the location and then do the check.

//Note from support:
the same situation occurs for:

• copySubtree
• swapLocation
• updating mainLocationId