Continuity mistake: In the scene at Le Grand Colbert restaurant in France the white rose in the vase on the table varies between a state of full bloom and being a small closed bud from shot to shot.
Continuity mistake: When Harry and Erica are having a picnic at the beach the sun light changes from shot to shot.
Deliberate mistake: When Harry is seen stepping outside of his hotel the evening after he arrives in Paris, behind him is the familiar Eiffel Tower gloriously illuminated against the night sky. Frequent Paris visitors or residents might recognise the hotel as the Plaza Athenee - to see the Eiffel Tower from there you'd need to be looking in the opposite direction from what we're shown.
Factual error: The audition scene for Erica's play would never take place in the theatre. Auditions and rehearsals are held in rehearsal halls, not the theatre. Yet they show the sets already built and installed, lighting and effects in place, and they reference the costumes being ready. This does not happen until the show is close to opening.
Continuity mistake: When a plate comes suddenly crashing to the ground, Erica is seen standing in her kitchen, above a white plate with a few bits of leftovers on that cracked plate. She is arguing with her sister about the "appropriateness" of the relationship between Harry and her daughter. As she bends down to pick it up, the plate is suddenly filled with red tomatoes and a heap of leftovers.