Copied frames

[default6mxchcexo8ug]

I have a Problem with added frames. The first two frames of a clip are the last frame of the previous clip. So the last frame is copied 2 times into the next clip. I don't understand the problem and how to solve it. 

Thanks in advance 

[Jeff Bellune]

• Do you have any transitions between the clips? Or a transition that used to be there but you took it out?
• Ensure there is no overlap between out and in points of clips if they are on different tracks.