You may delete a text track using the following procedure.
To delete a video text track:
Navigate to and select a video file.
Select View > Video Details.
The Video Details screen opens for the video file.
Select the Text Tracks tab.
Select an available text track type from the Classification list.
All text tracks of that classification are displayed.
Select the text tracks that you want to delete and click Delete or click File > Delete Text Tracks.
Click Save.
The Text Tracks list refreshes and the selected text tracks are no longer present.