Latex rendering error

[onion]

When I type Latex formula like this

$$
D_{n}=\left|\begin{array}{ccccc}
a & b & b & \cdots & b \\
b & a & b & \cdots & b \\
b & b & a & \cdots & b \\
\vdots & \vdots & \vdots & & \vdots \\
b & b & b & \cdots & a
\end{array}\right| .
$$

the rendering result looks like:

I think there is something wrong. The “|” is missing.

---

The “[” cannot render correctly as well

$$
\boldsymbol{A}=\left[\begin{array}{cccc}1& -1& -1& -1\\-1&1& -1& -1\\-1& -1&1& -1\\-1& -1& -1&1\end{array}\right]
$$

and the result shows like this:

[saf-dmitry]

@onion Both your examples work for me in both editing and reading mode. I think, this is a well known rendering issue, discussed in this forum before: The element is there, but is not visible at the current zoom level. This usually applies to elements, consisting of thin strokes, like fraction lines, equal signs, radicals (roots), etc. Try to zoom in (or out) and see if this has an effect.

P.S. Of course, it is still a bug nonetheless.

[onion]

Thank you very much! Solve it by zoom in