This can be caused by moving your .kma files to a new location without rebuilding your Songs.mdb. The only other thing that can cause this to happen is your Sound Card in your computer is missing drivers or damaged.
2) Make sure that you have deleted any old .hst Playlist files. Try creating a new one, by going to File\New. Now add a song to the new Playlist and see if it will play without errors.
3) Make sure that your Sound Card is working correctly on your computer, in other programs. If not, have the Sound card fixed by a technician.
Another thing that can cause this to happen with .Zip files that were converted in Hoster to the .Kma format. Try the following if you are having problems with Playing files that were converted from Zip.
When importing Zip files be advised that if the Zip files were created using Max Compression, under the Zip program. Then Hoster will not play that file. Hoster will import the song and you will not know it did not get imported correctly until you try playing the song. You can check to see if the file is bad before importing by trying to play it first. If the file is bad because of Max Compression you will get an Error Message. It is possible to uncompress the bad Max Compression file then re-zip the files using Normal Compression.