Questions about errors which in the end are caused by blank lines in math mode pop up on a regular basis (this is the latest one). Many new users haven't the experience to disentangle TeX error messages (or they simply ignore them), and in many cases the question describes what is optically going wrong, so that it is difficult to find a "standard duplicate"; for example, the linked question describes the problem as "the equation number goes to the wrong place".
Sometimes someone writes a one-line answer; sometimes the question gets closed as "solved in comments"; sometimes the answer is solved in comments but neither answered nor closed.
What do you think should be the preferred course of action?
\suppressmathparerror=1
. It might be a good idea to add this to the other TeX engines as well and think about making this the default in the LaTeX format. – Henri Menke Feb 3 at 12:47