54: Hint missing

The left curly bracket { is used together with the right curly bracket } for hints. A plain-text hint is expected in between the brackets. However, you used the left curly bracket at the very end of a block or immediately followed by the right bracket.

Solution

Add the missing hint text in between curly brackets. If you did not mean to annotate content with a hint, but want to use a left brace literally, you can prepend a backslash: \{