Wyler and jump cuts

One or two of the "continuity errors" listed are, I suspect a consequence of William Wyler's shooting style.

In simple terms: most directors would shoot a master shot covering the whole of the scene but also shoot close-ups, two-shots etc which is known as coverage. Wyler often tended to shoot only master shots. It can be an effective method but it has its drawbacks. If part of the scene in the middle doesn't work or has to be cut for length or it is necessary to use one take for the first half of the scene and another for the rest then there is no coverage to cut away to in order to smooth the cut.
In Wyler's films it's not unusual to see jump cuts (so named because the performers or background seems to jump slightly because of the discontinuity) - where the adjacent shots are too similar to each other. The Children's Hour for example has at least a couple of dialogue scenes where this happens.
Most directors before the last decade or two would have avoided jump cuts like the plague. (Unless it was a deliberate use for impact such as the discovery of one body in Hitchcock's The Birds). Wyler however didn't seem to worry enough to modify his style.

I suspect that this is the problem at the end of the first meeting with Nicky. Fanny closes the glass door and her head is suddenly against a door without glass as she sings his name. I think there was originally a continuation of the first shot with Fanny singing about Nicky as she walked down the corridor into her dressing room then closes the second door. For length or otherwise the middle part was cut, hence the two doors.
(Technically there is a very quick dissolve to try to soften the jump cut but it doesn't have much effect.)

Some other continuity errors may also not have been mistakes on the set but editing causing the reason for differences to be cut.