What computer operating system is involved?
Please verify that "video" is a video export from Premiere Elements 12/12.1 and not a Premiere Elements 12/12.1 project file that you are trying to open in Premiere Elements 11. Please excuse the question, but I did not want to take anything for granted. You cannot open a project file created in a later version in an earlier version.
Now if you are trying to import a Premiere Elements 12/12.1 video export into Premiere Elements 11, then please tell us in detail the export settings that you used in Premiere Elements 12/12.1. How are you importing the file into 11 - Add Media/Files and Folders?
Let us start here and then we can decide what next.