Please check the below to the files are compatible with COWON i9+.

* Supported File Formats : AVI, WMV,ASF
* Supported Video Codecs : Xvid SP/ASP, WMV 7/8/9
(screen resolution, frame rate, bit rate, and other options may affect
the playback of some clips)
* Video Resolution - 320x240, 30fps (recommended)
* Audio Codecs - MPEG1/2/2.5 Layer 3, WMA
* Subtitle - SMI

Please check the file information with COWON Media Center- JetAudio. If your file is not playing on COWON i9+ even though your file is encoded with those specifications, your file might be damaged. Please convert the file again by using COWON Media Center, JetAudio for use in COWON i9+.