> For the complete documentation index, see [llms.txt](https://docs.n8n.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.n8n.io/build/work-with-data/reference-data/link-data-items/item-linking-errors.md). # Item linking errors In n8n you can reference data from any previous node. This doesn't have to be the node just before: it can be any previous node in the chain. When referencing nodes further back, you use the expression syntax `$(node_name).item`.

Diagram of threads for different items. Due to the item linking, you can get the actor for each movie using `$('Get famous movie actors').item`.

Since the previous node can have multiple items in it, n8n needs to know which one to use. When using `.item`, n8n figures this out for you behind the scenes. Refer to [Item linking concepts](/build/work-with-data/reference-data/link-data-items/how-items-link-through-workflows.md) for detailed information on how this works. `.item` fails if information is missing. To figure out which item to use, n8n maintains a thread back through the workflow's nodes for each item. For a given item, this thread tells n8n which items in previous nodes generated it. To find the matching item in a given previous node, n8n follows this thread back until it reaches the node in question. When using `.item`, n8n displays an error when: * The thread is broken * The thread points to more than one item in the previous node (as it's unclear which one to use) To solve these errors, you can either avoid using `.item`, or fix the root cause. You can avoid `.item` by using `.first()`, `.last()` or `.all()[index]` instead. They require you to know the position of the item that you're targeting within the target node's output items. Refer to [Referencing previous nodes](/build/work-with-data/reference-data/reference-previous-nodes.md) for more detail on these methods. The fix for the root cause depends on the exact error. ### Fix for 'Info for expressions missing from previous node' If you see this error message: > ERROR: Info for expression missing from previous node There's a node in the chain that doesn't return pairing information. The solution here depends on the type of the previous node: * Code nodes: make sure you return which input items the node used to produce each output item. Refer to [Preserving linking in the Code node](/build/work-with-data/reference-data/link-data-items/preserving-linking-in-the-code-node.md) for more information. * Custom or community nodes: the node creator needs to update the node to return which input items it uses to produce each output item. Refer to [Item linking for node creators](/build/work-with-data/reference-data/link-data-items/item-linking-for-node-creators.md) for more information. ### Fix for 'Multiple matching items for expression' This is the error message: > ERROR: Multiple matching items for expression Sometimes n8n uses multiple items to create a single item. Examples include the Summarize, Aggregate, and Merge nodes. These nodes can combine information from multiple items. When you use `.item` and there are multiple possible matches, n8n doesn't know which one to use. To solve this you can either: * Use `.first()`, `.last()` or `.all()[index]` instead. Refer to [Referencing previous nodes](/build/work-with-data/reference-data/reference-previous-nodes.md) for more detail on these methods. * Reference a different node that contains the same information, but doesn't have multiple matching items.