SourceTree graph log does not show affected files of a commit

Question

I have a problem with my SourceTree. I can't see the affected files of a commit (see the image). My graph log displays only the diff of only one file, I can't select another one.

affected files in sourcetree

I would like to see the affected files on the left column and the diff of a selected file on the right column.

Can someone help me with this?

Thanks!