Final Cut Pro 7 error. BDMV contains unsupported media

Hi,
I have only problem when I try to import video files in Final Cut Pro 7.
What could be the cause of this annoying error message.
I need an expert advice so that I may fix this error.
Any help would be really appreciated.
Thanks in advance.

Warning “BDMV” contains unsupported media or has an invalid directory structure.
Please choose a folder whose directory structure matches supported media.
