Import Order & ID Remapping

ID maps

Every import records old-to-new ID maps per source site in #__murumigration_idmaps. Later imports rewrite their references through those maps -- which is why the order (users → articles → menus → modules) is load-bearing, not advisory.

What remaps automatically

• Module menu assignments (which pages each module appears on).
• Alias menu items (params.aliasoptions targets).
• com_content article links in menus (needs articles imported before menus).
• Unresolvable references are dropped with a warning, never silently linked to unrelated pages.

Tree safety

• Source nested-set values (lft/rgt/level/path) are never reused; the menu, category, and usergroup trees are rebuilt after import.
• Groups match by title; home-page conflicts arrive disabled with a warning.