Snapsot -- Your APPL_TOP has 31 files missing.

Dear All;

I need you help on following issue:
 
I executed snapshot at the end I receive following message:
 
Note: Your APPL_TOP has 31 files missing. Some of these files are referenced
in your file drivers but are missing in the APPL_TOP.
 
I want to know what are there missing file.
 
I will be waiting for your urgent reply.

Ata