Cannot render psd video

[Iris5C58]

Hi, I have edited a video file in photoshop. All fine. I can save as PSD. But cannot render. See the error message I get. I do not understand the problem. It is only me who has this file open in photoshop. How shall I be able to render when this file is closed.

[c.pfaffenbichler]

Is the mp4 open in some application? 

[Iris5C58]

no, only in photoshop as I have to open it there to be able to render 

[Iris5C58]

got it fixed now! the problem was the file I wanted to save had the same name. I had not renamed it. thought that was not necessary as it will be a different file type.