Meghan Markle missed the first leg of her High Court case against the Mail editor in Sunday's newspaper, it was announced on Friday.
A judge decided which parts of the case should be eliminated, although he said they could be revived later.
The case concerns a letter written by Meghan to her father, Thomas Markle, in August 2018, parts of which were published by Mail on Sunday and MailOnline the following February.
Meghan is seeking compensation for alleged misuse of private information, copyright infringement, and violation of the Data Protection Act by the Associated Newspapers, which is also the publisher of MailOnline.
Justice Warby delivered his decision following a request from Associated Newspapers last week.
He withdrew three allegations from the case, including that Associated Newspapers acted "dishonestly and in bad faith", that it "unearthed or deliberately provoked" conflicts between Meghan and her father and had an "obvious agenda of publishing intrusive or offensive "stories" about her.
"The rationale for attacking every aspect of the case is that the allegations are irrelevant by law, or inappropriately private, or that it would be disproportionate to litigate the issues raised, so that they are excluded from the scope of the case in case management." judge.
The first hearing was held remotely last week because of the coronavirus, with Meghan and her husband, Prince Harry, hearing from Los Angeles.
Meghan's lawyers accused Associated Newspapers of "harassing, humiliating, manipulating and exploiting" her father, whom they describe as "vulnerable".
The legal action was announced in October last year in a statement in which the Duke of Sussex accused the newspapers of a "relentless campaign" against his wife.
Meghan and Harry recently announced they were cutting the Daily Mail and three other British tabloids, giving them "no confirmation and zero commitment", saying their coverage was unfair.
Lawyers for the company that represents Meghan said the decision did not change the "essential elements" of the case.
“Although the judge recognizes that there is a claim for breach of privacy and copyright, we are surprised to see that his decision suggests that dishonest behavior is not relevant. We feel that honesty and integrity are at the heart of what matters; or when it comes to Mail on Sunday and Associated Newspapers, your lack, "said a Schillings spokesman.
"However, we respect the judge's decision as the strong case against Associated will continue to focus on the issue of a private, intimate and handwritten letter from a daughter to her father, published in the mail on Sunday."