There is such a thing as a VCAA Notice Error, however, the Supreme Court held in Sanders v. Shinseki (2010), that the error must be prejudicial and in sum a "harmful" error where but for the error the outcome would be manifestly different...the burden of proof being upon the veteran to show how the Notice error was harmful.
Relevant to the aforementioned, the Supreme Court held, "A specific statute requires the Veterans Court to “take due account of the rule of prejudicial error.” §7261(b)(2). In applying this statutory provision, the Veterans Court has developed its own special framework for notice errors. Under this framework, a claimant who argues that the VA failed to give proper notice must explain precisely how the notice was defective. Then the reviewing judge will decide what “type” of notice error the VA committed. The Veterans Court has gone on to say that a Type One error (i.e., a failure to explain what further information is needed) has the “natural effect” of harming the claimant; but errors of Types Two, Three, or Four (i.e., a failure to explain just who, claimant or agency, must provide the needed material or to tell the veteran that he may submit any other evidence available) do not have the “natural effect” of harming the claimant. In these latter instances, the claimant must show how the error caused harm, for example, by stating in particular just “what evidence” he would have provided (or asked the Secretary to provide) had the notice not been defective, and explaining just “how the lack of that notice and evidence affected the essential fairness of the adjudication.” Mayfield v. Nicholson, 19Vet. App. 103, 121 (2005)."
The Court further held, "To say that the claimant has the “burden” of showing that an error was harmful is not to impose a complex system of “burden shifting” rules or a particularly onerous requirement. In ordinary civil appeals, for example, the appellant will point to rulings by the trial judge that the appellant claims are erroneous, say, a ruling excluding favorable evidence. Often the circumstances of the case will make clear to the appellate judge that the ruling, if erroneous, was harmful and nothing further need be said. But, if not, then the party seeking reversal normally must explain why the erroneous ruling caused harm. If, for example, the party seeking an affirmance makes a strong argument that the evidence on the point was overwhelming regardless, it normally makes sense to ask the party seeking reversal to provide an explanation, say, by marshaling the facts and evidence showing the contrary. The party seeking to reverse the result of a civil proceeding will likely be in a position at least as good as, and often better than, the opposing party to explain how he has been hurt by an error. Cf. United States v. Fior D’Italia, Inc., 536 U. S. 238 , n. 4 (2002) (Souter, J., dissenting)."
Finally, the Court, "recognize[d] that Congress has expressed special solicitude for the veterans’ cause. See post, at 2 (Souter, J., dissenting). A veteran, after all, has performed an especially important service for the Nation, often at the risk of his or her own life. And Congress has made clear that the VA is not an ordinary agency. Rather, the VA has a statutory duty to help the veteran develop his or her benefits claim. See Veterans Claims Assistance Act of 2000, 38 U. S. C. §5103A. Moreover, the adjudicatory process is not truly adversarial, and the veteran is often unrepresented during the claims proceedings. See Walters v. National Assn. of Radiation Survivors, 473 U. S. 305, 311 (1985)."
In sum, the Supreme Court reversed the Federal Circuit's precedent, and provided a thorough framework in which to navigate VCAA errors which are deemed harmful, and to that extent prejudicial, and in so doing the Court noted the burden shifts to the appellant to show how the error was harmful and but for the error the outcome would have been manifestly different. So while not a CUE, there are grounds to allege error due to VA's failure to comply with VCAA proviso under 38 U.S.C. §5103A.