206: Crossed out string not closed

The left cross +- is used together with the right cross -+ to cross out text. You used the left cross without a corresponding right cross within the same block.

Solution

Add the missing right cross within the same block to cross out text. If you did not mean to cross out text, but want to use a literal plus sign followed by a hyphen, prepend a backslash: \+-

Here is a plus-minus sign to copy and paste, in case you are looking for one: ±