Near the end of the film Dennis Morgan takes a seat to see Joan Leslie's play. He is seated next to a young woman. The next time the camera cuts to him he is in the same seat, but sitting next to an older woman wearing completely different clothing.
Near the end, when Paul walks in to see Helen and Katie (after Katie told Helen she and Paul were to be married), the shot goes from the sisters facing each other to standing shoulder to shoulder back to facing each other.
Midway through the film, the trope of using a newspaper to cheaply jump the story ahead in time is used by opening a newspaper to an advertisement on page 3. However, the name of the newspaper printed on page 1 is different from the name of the newspaper printed on page 3.
When Paul is at the table talking to Laura, Helen, and Katie; Laura is smoking a cigarette with her left hand which the left hand has a glove on it. But on the following cut after Paul leaves the table with Katie; Laura is now smoking the cigarette with her right hand while taking off her left-hand glove.
Just moments after the opening night performance of a Broadway musical, several characters look at a print review of the show that appeared in weekly Variety. At that time, the publication did not run reviews of previews so there is no way this review could have appeared in print before curtain went down for first public performance.
At the party, the playwright is introduced as Laura Britton; in a newspaper headline later shown onscreen, she is identified as Laura Bithorn. It's likely that the latter was the character's original name; that it was changed on set, when she was introduced, to something that rolled more easily off the tongue; and that the prop newspaper wasn't changed to match.