chan_dahdi.c:5980 handle_alarms: Detected alarm on channels

Dears,
Kindly, i need your assist on a problem i am facing
i get "chan_dahdi.c:5980 handle_alarms: Detected alarm on channel 26: Yellow Alarm"
for all channels then i get "chan_dahdi.c:9868 handle_init_event: Alarm cleared on channel 26"
for all channels also and this means that the line is flapping
i am using ISDN and here is my configuration of chan_Dahdi.
[channels]
context=ISDN
usecallerid=yes
hidecallerid=no
callwaiting=no
usecallingpres=yes
callwaitingcallerid=yes
threewaycalling=yes
transfer=yes
canpark=no
cancallforward=yes
callreturn=yes
echocancel=no
echocancelwhenbridged=no
relaxdtmf=yes
;rxgain=0.0
;txgain=0.0
;group=1
;callgroup=1
;pickupgroup=1
immediate=no
pridialplan=dynamic
prilocaldialplan=dynamic

;Sangoma A104 port 1 [slot:4 bus:8 span:1]
switchtype=qsig
context=ISDN
group=1
echocancel=no
signalling=pri_cpe
channel=>1-15,17-25

group=5
echocancel=no
signalling=pri_cpe
channel =>26-31
outgoing: outgoing direction only

;Sangoma A104 port 2 [slot:4 bus:8 span:2]
switchtype=qsig
context=ISDN
group=1
echocancel=no
signalling=pri_cpe
channel=>32-46,48-62

;Sangoma A104 port 3 [slot:4 bus:8 span:3]
switchtype=qsig
context=ISDN
group=1
echocancel=no
signalling=pri_cpe
channel=>63-77,79-93

;Sangoma A104 port 4 [slot:4 bus:8 span:4]
switchtype=qsig
context=ISDN
group=1
echocancel=no
signalling=pri_cpe
channel=>94-108,110-124