1. Create host with numeric item.
2. Create graph with this item, or trigger with numeric function.
3. Edit item and change its type to text.
4. Graph and trigger remained on host.
5. Export Host
6. Delete/Rename Host and try to import exported XML.
Result:
Import failed. Error:
Cannot add a non-numeric item "item" to graph "Graph".
or
Incorrect item value type "Character" provided for trigger function.