Please read this FAQ Answer and provide us as much information as you can.
What is reporting that it is corrupt and unusable? Is it the Songs.mdb database? If so, read in the Manual how to
Rebuild the Songs Database.
We have never heard of imported KMA song files being damaged like this.
I expect, something has happened to your Hoster installation.
Run the Hoster Installation program again and select the MODIFY option. This will fix any problem that may exist with Hoster.
You should then be able to use your KMA files and continue importing your other discs.
Did you do anything to the computer - add hardware, install a new program, etc. - that may have caused this problem?