Chan_oss.c:498 warning

I get this warning a lot when running an extensions.conf file, how can i fix it please :

[Jan 31 04:29:04] WARNING[29967][C-00000003]: chan_oss.c:498 setformat: Unable to re-open DSP device /dev/dsp: No such file or directory

I am trying to use Playback file medias but when they are on playing i get like 15 warning messages of chan_oss.c:498 and i cannot hear any media.
In addition to this warning when i am dialing a phone using CLI :

chan_oss.c:789 oss_indicate: Don't know how to display condition 22 on Console/dsp

Sounds like you need to debug your Linux audio configuration. asterisk can’t open the dsp to play audio.