Reply to MP3's won't play on Traktor Pro 2 HELP

I have a library of about 3700 songs and 700 of them won't play. It's say's .mp3 could NOT be played due to a missing or corrupt file, unsupported format or DRM-protection.

I'm using the latest Traktor 2.1.1

All of these songs are legal and downloaded from beatport.

any advice or info would be appreciated.