60: Characters after link in metadata declaration

The arrow at the start of a metadata value -> marks the value as link. The arrow is expected to be followed by a filename/URI and only a filename/URI. In your metadata declaration the filename/URI is followed by further text on the same line.

Solution

Make sure your filename/URI is not followed by further text on the same line. Note that some characters like a space or a left curly bracket { terminate a filename/URI. You can enclose your filename/URI in backticks to prevent this, if your filename/URI contains such characters. If your filename/URI contains a backtick ` itself, the backtick needs to be prepended with a backslash: \`

Here are a two well-formed examples:

@ prev: ->`monday the first.nml`
@ next: ->wednesday.html

If you did not mean to assign a link, but want to use the characters -> literally at the start of a textual metadata value, you can prepend them with a backslash: \->