Short answer. Yes. The absence of a specific assignment of errors in the appellant's brief, or of the page references to the record that the rules require, is itself a listed ground for dismissing an appeal. The court may act on it without any motion from the other side.
What the law says
(f) Absence of specific assignment of errors in the appellant's brief, or of page references to the record as required in section 13, paragraphs (a), (c), (d) and (f) of Rule 44
Rule 50, Section 1 — Grounds for dismissal of appeal. Read the full provision →
Why the assignment of errors carries so much weight
An appeal is not a fresh trial. It is a review of identified mistakes, and the assignment of errors is what identifies them. That is why the rule treats its absence as a ground for dismissal rather than a defect in form: without it, there is nothing for the appellate court to review. The requirement is for a specific assignment, so a general complaint that the judgment was contrary to law and the evidence does not do the work the rule expects.
Page references are part of the same ground
The same paragraph puts missing page references to the record on exactly the same footing as a missing assignment of errors. The rule ties this to the particular parts of the brief where the rules on appellate briefs demand those references — the statement of the case, the statement of facts, and the argument. The reasoning is practical: an assertion about what the record shows, with no pointer to where it shows it, cannot be verified, and the court is not obliged to hunt for it.
The dismissal is discretionary, but do not rely on that
An appeal may be dismissed on this ground, and the court may raise it on its own motion or on that of the appellee. Discretion exists, and a brief with a genuine but imperfectly framed assignment of errors stands differently from one with none at all. Still, a brief is the appellant's main opportunity to be heard, and treating these requirements as optional wastes it. Errors that are never assigned generally go unconsidered even when the appeal survives.
Fixing it before it becomes fatal
If the brief has already been filed and the defect is real, the practical move is to seek leave to file an amended brief promptly, rather than waiting to see whether anyone objects. Set out each error as a separate, concrete proposition about what the court below got wrong, and give the record page for every factual assertion. That is not merely compliance — it is the form in which appellate arguments are actually persuasive.