When I type the following code in a comment:
$$\require{AMScd} \begin{CD}\Gamma(X,\mathcal O_X) @>>> \mathcal O_{X,x}\\ @AAA @AAA \\ \Gamma(Y,\mathcal O_Y) @>>> \mathcal O_{Y,f(x)} \end{CD}$$
$$\require{AMScd}
\begin{CD}
\Gamma(X,\mathcal O_X) @>>> \mathcal O_{X,x}\\
@AAA @AAA \\ \Gamma(Y,\mathcal O_Y) @>>> \mathcal O_{Y,f(x)}
\end{CD}$$
to generate: $$\require{AMScd} \begin{CD}\Gamma(X,\mathcal O_X) @>>> \mathcal O_{X,x}\\ @AAA @AAA \\ \Gamma(Y,\mathcal O_Y) @>>> \mathcal O_{Y,f(x)} \end{CD}$$
I end up with a warning box stating: Only one additional @user can be notified; the post owner will always be notified. It seems that it confuses between @>>> in the text mode and @>>> in the math mode.
This really should be fixed.
