Insert cover error

[charlie14]

When searching and inserting missing covers I get this error message:
java.io.FileNotFoundException: F:\06. U - Z\V\Ally Venable Band\2015 - Train Wreck Blues\cover.png (The system cannot find the specified path).
What is the reason?

P.S.
And I also get this error: java.io.FileNotFoundException: /FTP/02.Musicbase/06. U - Z/V/Antonello Venditti/2001 - Circo Massimo/cover.png (Permission denied)

I use Subsonic under WIN10 local with external hard drive