More information needed for someone to help... click these links and provide the
Exactly what is inside the file?
Read Bill Hunt on a file type as WRAPPER http://forums.adobe.com/thread/440037
What is a CODEC... a Primer http://forums.adobe.com/thread/546811
What CODEC is INSIDE that file? http://forums.adobe.com/thread/440037
Report back with the codec details of your file, use the programs below... a screen
Does your project match the video?
If you have a red line over the timeline after importing a video and before adding any
effects... your project is wrong for your video... read above about codecs
Please NOTE that the PPro CS6 screen may look a bit different
For CS5 and later, the easy way to insure that your video and your project match
See 2nd post for picture of NEW ITEM process http://forums.adobe.com/thread/872666
-and a FAQ on sequence setting http://forums.adobe.com/message/3804341