112: Malformed option

You started a line with a left curly bracket { which turns the block into a multiple-choice question and marks an option in it. An option consists of a key enclosed in curly brackets and an answer. It seems that the right curly bracket at the end of the key is missing in your case.

Solution

Make sure you have got a right curly bracket for every left curly bracket. Here is an example:

What’s the square root of nine?
{ } one
{ } two
{x} three
{ } four

If you did not mean to offer an option and wanted to write a left curly bracket literally, you can prepend it with a backslash: \{