There may be various reasons causing this. To help solve this problem, please confirm below info:
1) Make sure that the file format is supported.
2) Make sure that the video file have not been damaged.
3) Please drag your original video to our software to check if our software can load it successfully.
4) Make sure that the files play well on your computer, and save them to a local disc with a simple file name, like C: usertest.MOD.
If this doesn't work, please contact us at support@aiseesoft.com with a copy of one file you use for analysis. Analyzing the original video will help us solve your problem soon.