You may want to check your list of attributes or levels for a operator sign (such as > or <) in the display text. If this is the case, you need to use the equivalent html entity code instead. Below is a partial table of commonly used codes.
ASCII Character | HTML Entity Code | Description |
---|---|---|
< | < | less-than |
> | > | greater-than |
A more complete list of common ASCII characters and their HTML entity equivalents is found here: http://www.freeformatter.com/html-entities.html