Aerial Analyst uses Video Mixer 9 which is part of DirectX9. Another problem can be the absence of corresponding codec. To troubleshoot the problem do the following.
1 Run pw7 from the installation directory with the same video file. If it fails to play, you do not have corresponding codec.
2 Run pw9 from the installation directory with the same video fiel. If it fails to play, you do not have DirectX9 installed, or the installation might be not fully successful (e.g. video card is not fully supported)
3 If pw9 can play video but Video Viewer still cannot play (unlikely), it is a bug which is currently being worked on. It will be fixed in very near future.