Could someone test the * extension please?

Hello group,

Could someone test this scenario with entering a string of dtmfs starting with a star and ending with a # ?

exten => 56,1,Set(Menucount=3)
exten => 56,n,Set(string)
exten => 56,n,NoOp(${string})
exten => 56,n,Ringing
exten => 56,n,Answer
exten => 56,n,Background(/home/astfiles/smenu)
exten => 56,n(reset),Set(TIMEOUT(digit)=5)
exten => 56,n,Set(TIMEOUT(response)=3)
exten => 56,n,GotoIf($[${Menucount} > 0]?:hangup,1)
exten => 56,n(towaitexten),WaitExten

exten => i,1,Set(string=$[${string}${INVALID_EXTEN}])
exten => i,n,NoOp(${string})
exten => i,n,Goto(56,reset)

exten => *,1,Set(string=$[${string}${EXTEN}])
exten => *,n,NoOp(${string})
exten => *,n,Goto(56,reset)

exten => #,1,NoOp(${string})
exten => #,n,Hangup

exten => 1,1,Hangup

This scenario should gather a string of dtmfs and display it in the cli after a # is pressed. It doesn’t work. Te source channels is mISDN
This is the error returned on cli of Ast 1.2.5

– Invalid extension ‘*’ in context ‘ctrunk’ on mISDN/1-2
May 22 13:04:56 WARNING[6838]: ast_expr2.fl:183 ast_yyerror: ast_yyerror(): syntax error: syntax error, unexpected TOK_MULT, expecting TOK_MINUS or TOK_COMPL or TOK_LP or TOKEN; Input:
Thank you,