Unable to open DAHDI pseudo device

Good Day!
I installed a single server setup on the other site, when i test it to call by logging in the agent I got this error
WARNING[13552]: app_meetme.c:1259 build_conf: Unable to open DAHDI pseudo device
and it hung up and the next error is this
WARNING[13610]: app_meetme.c:4840 admin_exec: Conference number '8600051' not found!
thank you in advance.
I installed a single server setup on the other site, when i test it to call by logging in the agent I got this error
WARNING[13552]: app_meetme.c:1259 build_conf: Unable to open DAHDI pseudo device
and it hung up and the next error is this
WARNING[13610]: app_meetme.c:4840 admin_exec: Conference number '8600051' not found!
thank you in advance.