Difficulties when estimate a DSGE model

Dear all,
I am estimating a economic DSGE model with DYNARE,and i meet problems as follow:
??? 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 58
   ix2, ilogpo2, ModelName, MhDirectoryName, fblck, fline, npar, nblck, nruns,
  NewFile, MAX_nruns, d ] = ...

  Error in ==> dynare_estimation_1 at 871
  Error in ==> dynare_estimation at 62

  Error in ==> monetary at 247

   Error in ==> dynare at 132
  evalin('base',fname) ;
  Since i am a beginner of dynare,i don't know how to solve the problem.I need your help,thank you very much.
  <a class='attachment' href='/uploads/default/original/2X/c/cf61d62af2fcf1260f3c1485ba6024ff2d9cb38e.mod'>monetary.mod</a> (2.21 KB)
  <a class='attachment' href='/uploads/default/original/2X/5/5012bfb63251bae36422266eb61e8cac42801b22.m'>data_2ond.m</a> (2.52 KB)

Use mode_compute=6 (search the forum using Google on the issue, there are countless posts). Moreover, check the timing for k, particularly in the production function and the law of motion.

Thank you for your reply,i can run the mode file successfully now.Best wishes!

i am trying to stimate a dsge model but the dynare told me: Impossible to find the steady state.
i dont know what is wrong with my code
please help me
x1.mod (1.61 KB)

@salarcon Please recheck your model. Your exogenous processes are most surely wrong. Why do you have

log(Px) = rho*Px((-1))+ e; log(Pm) = mrho*Pm((-1));
with log on the left and levels on the right side?