89: Multiple consecutive hints

The left curly bracket { is used together with the right curly bracket } to provide a hint. While it may be combined with a link, it is combined with a second hint in your case, which is not allowed.

Solution

Consider merging multiple hints into a single hint. If you did not mean to annotate content with a hint but want to use curly brackets literally, you can prepend them with a backslash: \{ and \}