I have an extension 1202 defined in [default], which is connected to a Digium TDM400P (DAHDI/1-1)

exten => 1202,1,NoOp(${CALLERID(all)})
exten => 1202,n,Dial(DAHDI/1,20,rtT)
exten => 1202,n,Macro(voicemail,${EXTEN})
exten => 1202,n,Hangup()

In buttons.conf I have configured it as:

[DAHDI/1]
type=extension
label=Tobie <1202>
channel=1

When I want to dial that extension (via FOP2) it can't find it.
Asterisk executes: "s@default"

      > Channel SIP/1001-00000003 was answered.
  == Starting SIP/1001-00000003 at default,trunk,1 failed so falling back to exten 's'
    -- Executing [s@default:1] NoOp("SIP/1001-00000003", "Time=18.12") in new stack
    -- Executing [s@default:2] NoOp("SIP/1001-00000003", "Callerid name=Henk Nokia") in new stack
    -- Executing [s@default:3] NoOp("SIP/1001-00000003", "Callerid number=1001") in new stack
    ..........
    ..........

But I don't have an exten 's' in default.

I have an exten 's' in a context [i], which is included in context [default]
So this is what is executed:

[incoming]
exten => s,1,NoOp(Time=${STRFTIME(${EPOCH},,%H)}.${STRFTIME(${EPOCH},,%M)})
exten => s,n,NoOp(Callerid name=${CALLERID(name)})
exten => s,n,NoOp(Callerid number=${CALLERID(num)})

What am I doing wrong? Is it the definition in buttons.conf ? Or something else?

Thanks very much for your answer.
This is ok now. :D