I am running X3e on a Dell XPS14 computer.  My bandmate is running the identical software (X3e) on his studio desktop.  We have created a live set with video.  It runs and looks perfect on his system.  In transferring the project to the laptop, the audio plays fine, but no video is viewable in any window size.  This is a problem since we plan on using a laptop for a live show.  The only difference in our systems is that he is running windows7 and I have Windows8.1.  I've updated all my drivers and have the latest bios installed.  I am out of ideas....any thoughts on what might be going on?  The video files is in mpg format, but I can't get ANY video to play in sonar.  The screen is just black (though the project plays).  I DID make sure I re-imported the video on the laptop since it does not seem that sonar saves video with a project file.  Keep in mind, NO video from any file, is playing.  BTW, the video plays fine in VLC and WMP.
 
THANKS!
Steve

Almost certainly the codec is not installed on your computer.
 
Sometimes this is solved by installing QuickTime if that includes the codec you need.

and the Klite codecs pack is also worthwhile 

http://www.free-codecs.co.../K_Lite_Codec_Pack.htm

Tried installing both the klite codecs and quicktime with no change in DAW behavior.  Video still shows black.  However, it now does seem to play wmv videos.  UNfortunately, the video I am in need of playing is MPEG2.  At least I have a clunky solution where I can convert it and play, but it is frustrating.
 
S

Mark and i have respectfully agreed to disagree about the merits of internet codec packs, but a more direct solution instead of installing a lot of codecs blindly is to idenify the one you actually need.  This free utility will analyze the file you have to make that determination : http://www.headbands.com/gspot/
 
i do agree that k-lite, in my experience , seems to be malware free, which is more than i can say for most.

Dub and I are old friends and like minded friendly foes on this. 
 
If we can help then we will.
 
KLite is Malware free, off the top of my head there are two malware(ish) files but a false positive.
 
Dubs link to the free utility is a must.

OP, which video engine are you using within Sonar?
 

https://www.cakewalk.com/...roubleshooting.10.html

Media Foundation with K-Lite works well for me, DirectShow was a disaster but its going to depend on what you have on your system.
 
A bit of trial and error and settle for whats best.