I can successfully load an avi file for editing. After the file has loaded the preview video window shows the opening still from the video. When the play button is pressed the preview window immediately turns black as the video plays. I know the video is playing as the video slider marker moves along the timeline. Also the current time is displayed in the current slider time control box. However the puzzling aspect is that if I left click and hold anywhere in the preview window the video plays with vision as long as you hold the left click. At the same time that the video is playing with vision, the time slider and current time freezes until I release the left click and the window goes black and the times jumps forward.
I have been using the avi trimmer for a number of years on the same machine running Windows 7and this problem only developed in the last few weeks. The avi files all play in WMP, DIVX player and VLC but interestingly not in Real Player where a black screen is displayed when playing a file with a flickering picture if the Real Player window is left clicked.