Short answer. No — once a court has allowed a will and that allowance is not overturned on appeal, the law treats the will's due execution as conclusively settled, closing off later challenges on execution grounds. The only way to reopen that question is through an appeal from the order of allowance itself, taken within the time the law permits.
What the law says
No will shall pass either real or personal estate unless it is proved and allowed in the proper court. Subject to the right of appeal, such allowance of the will shall be conclusive as to its due execution.
Rule 75, Section 1 — Allowance necessary. Read the full provision →
What allowance actually decides
When a court allows a will, it is ruling specifically on due execution — that the document was signed by the testator, that it was witnessed the way the law requires, and that the testator had the capacity to make it. That determination is what the allowance decree fixes. Once the decree stands, the law does not let someone come back later and argue, for instance, that a required witness was missing, that the signature was forged, or that the testator was not of sound mind when the will was made. Those are exactly the questions a probate proceeding exists to settle once and for all, and allowance is the court saying they have been settled.
Why the law makes this conclusive
Without a rule like this, a will's validity could be relitigated indefinitely, with every distribution to heirs left hanging over a dispute that was already tried and decided. Making the allowance conclusive as to due execution gives the estate, the heirs, and anyone dealing with them a fixed point to rely on. It also reflects that a probate court does not decide execution informally — a full hearing on notice to interested parties precedes allowance, so the conclusiveness attaches to a matter that was actually litigated, not merely assumed.
Appeal is the one door still open
The rule is not absolute — it applies subject to the right of appeal. Someone who believes the will was not properly executed can still challenge the allowance by appealing that particular order. If the appeal succeeds, the allowance can be reversed and due execution reopened. But once the period to appeal has run without one being taken, or an appeal is filed and rejected, the question of due execution is closed. There is no separate, later proceeding where the same execution objections can be raised again.
What conclusiveness on execution does not cover
Conclusiveness attaches only to due execution — it does not immunize everything about the estate from further dispute. Questions distinct from execution, such as whether a particular disposition in the will conflicts with what the law reserves for compulsory heirs, whether the will was later revoked, or how the estate's property should actually be distributed among the heirs, are not resolved simply because the will was allowed. Allowance answers one question — was this validly executed — and leaves the rest of the settlement proceeding to work out everything else.