One possible reason is that the macro is not supported by MathJax. If this is the case then macro will appear as plain red text in with the rendered TeX.
Another possibility is that the field has Markdown enabled, but not all the backslashes in the TeX notation were escaped. This can lead to some layout problems, such as all the elements of a matrix appearing in 1 row instead of many. Similarly, underscores should also be escaped with a backslash when they are used at the beginning or the end of a word: '\_'.
For more details on the difference between OpenReview's TeX support and other systems, see here.
OpenReview uses the open source library MathJax to render TeX content, and there are some key differences between it and other systems. First and foremost, the TeX input processor implements only the math-mode macros of TeX and LaTeX, not the text-mode macros. So, for example, MathJax does not implement \emph
or \begin{enumerate}...\end{enumerate}
or other text-mode macros or environments. You must use Markdown (if enabled) to handle such formatting tasks.
Second, some features in MathJax might be limited. For example, MathJax only implements a limited subset of the array environment’s preamble; i.e., only the l, r, c, and | characters alongside : for dashed lines — everything else is ignored.
When adding TeX content to a Markdown enabled field, it is important that all backslashes (\) are escaped (i.e. replaced with \\) to prevent Markdown from stripping the backslashes before the TeX notation is parsed. If Markdown is not enabled, this is not necessary.
Keep in mind that your mathematics is part of an HTML document, so you need to be aware of the special characters used by HTML as part of its markup. There cannot be HTML tags within the math delimiters as TeX-formatted math does not include HTML tags. Make sure to add spaces around any <
or >
symbols to ensure they are not treated as open tags.