error index exceeds matrix dimensions

getting error index exceeds matrix dimensions at line h = H{m}; %index exceeds matrix dimensions inside the for loop

    1.% function [rho] = blah(start,rho0)
    %UNTITLED2 Summary of this function goes here
    %   Detailed explanation goes here
load definitions.mat
load parameters.mat
[a,adag,II,A,Ad] = Nho_stuff(Nho,gam);
whos a adag II A Ad
whos start
H = Hamiltonian(start);
whos H
nt = Nt+1;
rho=cell(nt,1);
rho{1}=rho0;
m=1;
dt=tunit;

% tind=1:1:Nt;
% time=tind*tunit;
% whos H{1}
   %h=zeros(length(rho0));

for i = 1: nt
  if(abs(mod(i,C))<eps) %mod(i,C)=0
      m=m+1;
  end
  h = H{m}; %index exceeds matrix dimensions
%     h=H(m);   %defines it as a cell rather than a matrix
%     h=cell2mat(H(m)); %index exceeds matrix dimensions
  ro=rho{i};

    ihdt   = -1i*h*dt;
    ih2dt2 = 0.5*ihdt*ihdt;
    droh =  ihdt*ro  - ro*ihdt- 2*(ihdt*ro*ihdt) + ro*ih2dt2 + ih2dt2*ro; % 0;% 
    dro = droh + (A*ro*Ad-(1/2)*Ad*A*ro-(1/2)*ro*Ad*A)*dt;

    rho{i+1}=rho{i}+dro;
    rho{i+1}=rho{i+1}/real(trace(rho{i+1}));

end
end

Remaining files could be found here total code

[Stephen23]

@Tejas Shetty: it is time for you to do some debugging. Start by looking at the size of H, and thinking about why you expect index m to be <= the number of elements of H.