When Clare arrives at Aunt Bridget's big house in England, the front doors are arched doors and window panes; when she walks through the doors, they are square window panes with a Christmas wreath on each door.
When Clare is video chatting with Sarrah the mic is off, shows a line thru the mic symbol. There is no way Sarrah could possibly hear what Clare is saying.
Around the half of movie, Claire and Aunt Bridget walk down on the old street. On their left side there are cafe tables and four persons are sitting. Three of them literally stare at camera and them, and even start to talk before camera cut them and is zoomed to Claire and Aunt Bridget.
Clare looks toward the windows and says it's snowing, but the windows all have closed curtains.
The electrical sockets are not correct for England.
Around the half of movie, Claire and Aunt Bridget walk down on the old street. There are some 10 cars parked on the both sides of the street, and they all have left steering wheel which is impossible in England. However it was filmed in Belgrade, Serbia, so cars have left steering wheel. Furthermore, they blurred vehicle registration plates on the left side of the street, but missed on the right as you can clearly see Serbian vehicle registration plate.
Also, few seconds later in the close shot which they didn't blur enough, you can see again Serbian vehicle registration plate on the parked Audi A6.
The name of the Boston-Cambridge Ballet Company director, as seen by the Facetime notification on Clare's laptop, is Sarrah. In the end credits, it is listed as Sarah.