Ask in the PPro forum and provide info about your system, your camera and so on. nobody can even begin deciphering your problem based on such vague info.
Here sis the latest info I have regarding mod file support:.mod
Camcorder Recorded Video File // Tapeless MPEG format from some JVC, Panasonic and Canon SD and/or HDcameras // Import=Yes
If you're on windows, the first thing to try is installing and updating quicktime as needed. If it still fails, then I'll need ot get a file from you. Also keep in mind that codecs influence support too, in addition to whatever file format it may be wrapped in.