With more than 86 million followers, Perry is the world's most popular person on Twitter but she has struggled to win over a crucial market of two -- a pair of elderly nuns who oppose selling the complex to the singer for $14.5 million.
The nuns, who voiced distaste for the "I Kissed a Girl" singer, had signed a deal to sell the convent to a restaurant owner, Dana Hollister.
But Los Angeles Superior Court Judge Stephanie Bowick in a brief hearing on Wednesday invalidated the deed.
Her move came in response to the pleas not just of Perry but of the archdiocese, which said that the two sisters, Rita Callahan and Catherine Rose Holzman, did not have authority to complete the sale.
The archdiocese said that Perry had offered the $14.5 million in cash, while Hollister had only paid $100,000 of a promised $15.5 million -- $10 million for the former convent and $5.5 million to buy out a property on the complex.
The convent, known as the California Institute of the Sisters of the Most Holy and Immaculate Heart of the Blessed Virgin Mary, once had more than 100 nuns.
The sisters no longer live on the property but Callahan and Holzman argued that they had sole authority under the institute's bylaws.
Perry, who grew up as a born-again Christian but is known for her support of gay rights and sultry songs such as "Teenage Dream," has visited the nuns and sung for them in a fruitless bid at persuasion.
