246: Metadata name not declared with link value
The combination of arrow and squirrel ->@ marks a metadata link. It links to the address that was assigned to the metadata name in a metadata declaration. The metadata name has been declared in your case, but not with a link as value.
Solution
Make sure that there is an arrow -> before the address in the metadata declaration to mark it as link like in the following example:
@ next: ->/page-3.nml
Click to go to the `next page`->@next.