Weird error concerning estimation examples in the User Guide

[lemonadelaur]

Hello all,

I have confronted with several problems when I tried the examples in the estimation parts of the User Guide. (RBC_Est in Chap 5 & fs2000ns in Chap 6).
1. When I use the models files downloaded from the Dynare website, both of them showed the following errors:
POSTERIOR KERNEL OPTIMIZATION PROBLEM!
(minus) the hessian matrix at the "mode" is not positive definite!
=> posterior variance of the estimated parameters are not positive.
You should try to change the initial values of the parameters using
the estimated_params_init block, or use another optimization routine.

RESULTS FROM POSTERIOR MAXIMIZATION
parameters
prior mean mode s.d. t-stat prior pstdev

alpha 0.350 0.3357 0.0069 48.4901 beta 0.0200
beta 0.990 0.9900 0.0003 2862.5816 beta 0.0020
delta 0.025 0.0251 0.0027 9.2494 beta 0.0030
psi 1.750 1.7506 0.0199 87.7947 gamm 0.0200
rho 0.950 0.9503 0.0071 133.0992 beta 0.0500
epsilon 10.000 10.0000 0.0000 0.0000 gamm 0.0030
standard deviation of shocks
prior mean mode s.d. t-stat prior pstdev

e 0.010 0.0110 0.0003 34.0724 invg Inf

Log data density [Laplace approximation] is 6754.144314.

??? Error using ==> chol
Matrix must be positive definite.

Error in ==> metropolis_hastings_initialization at 52
d = chol(vv);

Error in ==> random_walk_metropolis_hastings at 43
[ ix2, ilogpo2, ModelName, MhDirectoryName, fblck, fline, npar, nblck, nruns, NewFile, MAX_nruns, d ] = ...

Error in ==> dynare_estimation_1 at 1050
feval(options_.posterior_sampling_method,'DsgeLikelihood',options_.proposal_distribution,xparam1,invhess,bounds,gend,data,...

Error in ==> dynare_estimation at 62
dynare_estimation_1(var_list,varargin{:});

Error in ==> RBC_Est at 147
dynare_estimation(var_list_);

Error in ==> dynare at 132
evalin('base',fname) ;

2. When I changed to mode_compute=6 as suggested by some posts, neither of them could work. The errors are:
MCMC Diagnostics: Univariate convergence diagnostic, Brooks and Gelman (1998):
??? Error: File: c:\dynare\4.1.0\matlab\McMCDiagnostics_core.m Line: 36 Column: 8
Functions cannot be indexed using {} or . indexing.

Error in ==> McMCDiagnostics at 100
fout = McMCDiagnostics_core(localVars,1,npar,0);

Error in ==> dynare_estimation_1 at 1055
McMCDiagnostics(options_, estim_params_, M_);

Error in ==> dynare_estimation at 62
dynare_estimation_1(var_list,varargin{:});

Error in ==> RBC_Est at 147
dynare_estimation(var_list_);

Error in ==> dynare at 132
evalin('base',fname) ;

I am a little bit desperate now... Thank you so much for your help!

Best,
Laura