AVI is a wrapper, what is inside YOUR wrapper - Exactly what is INSIDE the video you are editing?
Codec & Format information, with 2 links inside for you to read http://forums.adobe.com/thread/1270588
Report back with the codec details of your file, use the programs below... A screen shot works well to SHOW people what you are doing
https://forums.adobe.com/thread/1070933 for screen shot instructions
Free programs to get file information for PC/Mac http://mediaarea.net/en/MediaInfo/Download
elements and .avi
Please let us know what kind of .avi you are trying to use in Premiere Elements 11. What computer operating system is your Premiere Elements 11 running on?
If it turns out you are working with AVCHD.avi, then you are dealing with a file that Premiere Elements does not support. Premiere Elements does support files that use AVCHD video compression and can support files with an .avi file extension (wrapper/container format), but it does not support the combination of the two. Other problematic .avi files could be
A user ran into this AVCHD.avi situation the other day and posted a suggested software for the conversion of AVCHD.avi to a more compatible format or to be used as video editor for AVCHD.avi as is. I will post that link with that information if needed.
We will be watching for your follow up.