Simulink size mismatch problem

Simulation stopped due to size mismatch error on dimension 2: expected 1 but actual size is 6912.

The debugger pointer (green arrow) is on the line: OUT_decode=zeros(24*floor(length(IN_enc)/32),1)';

At the beginning I tried to work with matrices format on the line "OUT_decode(1+(ii-1)*24:24*ii)=k(1:24);" but gut a weird error- Matrix(matrix) subscript turned out to be a vector(vector) subscript simulink

here is the relevant code:

function OUT_decode  =viterbi_decode_obj(IN_enc,R)
%#codegen

% IN_enc=IN_enc';
persistent  tb_len trellis 
if(isempty(tb_len))   
  tb_len=length(IN_enc)/2; 

    trellis=poly2trellis(7,[133 171]);
   end
   switch R
        case{9,18,36,54}    % R=3/4
          OUT_decode=zeros(24*floor(length(IN_enc)/32),1)';

         for ii=1:floor(length(IN_enc)/32)
         k= viterbi_dec_3(IN_enc((1+(ii-1)*32):ii*32),16); 
         OUT_decode(1+(ii-1)*24:24*ii)=k(1:24);
         end
     otherwise
         OUT_decode=zeros(1,2)';
 end    % end switch

% OUT_decode(1:end)=OUT_decode1(1:end);
 return

function [OUT_dec]  =viterbi_dec_3(IN_enc,tb_len)
%#codegen
% OUT_dec=(zeros(24,1));
  persistent hDec
  if(isempty(hDec)) 
   trellis=poly2trellis(7,[133 171]);
   hDec = comm.ViterbiDecoder(trellis,'InputFormat','Hard','PuncturePatternSource','Property', 'TerminationMethod','Truncated','PuncturePattern',[1;1;1;0;0;1],'TracebackDepth',24 );
  end
 IN=IN_enc;
 OUT_dec=double(zeros(tb_len,1));
 OUT_dec = step(hDec, IN);
%  OUT_dec=OUT_dec';
return