Did the accessibility checker cause duplicate closed captions?

Good news first: the accessibility checker doesn't create captions — it only flags where they're missing. So the duplicates came from somewhere else.

The usual culprits, in order:

1. Every line is in the caption editor twice. Select the audio or video, go to Audio/Video Tools → Options → Closed Captions, and scan the rows. Sometimes an import runs twice and doubles everything.

2. Two caption sources stacked up. If you generated captions with AI Assistant and then also imported a caption file, you've got two tracks. In the same editor, clear out one of them.

3. Text baked into the video itself. If your source video already has words burned into the picture, the CC layer sits on top of it and reads as a duplicate. Quick test: turn the CC button off in Review 360. If the text is still there, it's in the video — and that one gets fixed in the source video, not Storyline.

Number 1 is the one I see most. Worth a look.