Seth B. Tillman and C. Stephen Biglar are the authors of:  "Void or Voidable? – Curing Defects in Stock Issuances Under Delaware Law, available on SSRN  here.

A partial quote from the abstract summarizing the article follows:

It is not unusual for practitioners reviewing a Delaware corporation’s stock records to find omissions or procedural defects raising questions as to the valid authorization of some of the outstanding stock. Examples of such omissions and defects are limitless, but not infrequently found examples include the absence of board resolutions authorizing the issuance of stock shown by the transfer books as having been issued, the absence of evidence that issuances were properly authorized by the requisite votes of the board or, if required, by the stockholders, the absence of evidence that the consideration to have been received by the corporation in exchange for the stock was in fact received, the issuance of more shares than were authorized by the certificate of incorporation at the time, the issuance of stock prior to the filing of the charter amendment or certificate of designations authorizing or creating the stock, and similar procedural and substantive irregularities. Not infrequently, these defects occurred some time ago, and the stock in question may have changed hands multiple times since issuance.

Confronted with such irregularities, most corporate lawyers’ first instinct would be to attempt to correct the defect through board and, if necessary, stockholder, ratification of the defective issuance, with the intent of putting the parties in the positions they thought they were in prior to discovering the irregularity. However, Delaware courts have not always viewed defects in stock issuances as being curable by ratification. In a number of leading cases, the Delaware Supreme Court has treated the statutory formalities for the issuance of stock as substantive prerequisites to the validity of the stock being issued, and has determined that failure to comply with such formalities renders the stock in question void. A finding that stock is void means that defects in it cannot be cured, whether by ratification or otherwise. Thus, practitioners finding defects in stock issuances are put in the uncomfortable position of having to make a judgment whether the defect is one that renders the stock void, in which case ratification is not an option, or voidable, in which case ratification is an option. Unfortunately, the decisions issued by the Delaware courts have not afforded certainty in this critical area. Indeed, a recent decision of the Court of Chancery acknowledges that although "Delaware law is replete with cases" discussing the void-voidable distinction, the law as to when and whether a defective stock issuance can be cured "is not as clear as it could be."