Error with Molpro Calculation

[Elizabeth Aubin]

Hi, 

I am trying to run a molpro calculation with this input file. I keep getting a "warning small diagonal hessian element for rotation" and then the calculation stops. I believe it has to do with the number of occupied and closed orbitals that I have specified. What would someone suggest? 

*HC50 !has 39 electrons so it is an odd molecule

   memory,160,M

   basis= {spdf,O,cc-pVQZ;spdf,C,cc-pVQZ;spdf,H,cc-pVQZ}

     geometry={

     O1;

     C1,O1,r1;

     C2,C1,r2,O1,a1;

     C3,C2,r3,C1,a2,O1,b1;

     C4,C3,r4,C2,a3,C1,b2;

     C5,C4,r5,C3,a4,C2,b3;

     H,C5,r6,C4,a5,C3,b4;

     }

      oneau=0.5291772108;

      r1=1.10417213 Ang;

      r2=1.43 Ang;

      r3=1.18100268 Ang;

      r4=1.38561921 Ang;

      r5=1.18159374 Ang;

      r6=1.05373660 Ang;

      a1=179.05326215;

      a2=179.04576217;

      a3=179.99846807;

      a4=179.99811635;

      a5=179.99894747;

      b1=145.55807266;

      b2=198.54138235;

      b3=178.19520306;

      b4=182.14040527;

      {hf;option,maxit=350; wf, NELEC=40,  spin=0, CHARGE=-1 ;orbprint, 20;} !do this because we want even molecule

      {multi;closed,19;occ,24;CPMCSCF,GRAD;wf,NELEC=39, spin=1, CHARGE=0,sym=1;orbprint, 20;}

      {optg;ACTIVE,r1,r2,r3,r4,r5,r6,a1,a2,a3,a4,a5,b1,b2,b3,b4;}

      put,xyz,hccccco.xyz

      {freq}