Error in default port dimensions function of S-function 'SimulacionPIA/MATLAB Function'. This function does not fully set the dimensions of output port 2

Hi guys, im doing an analysis on a arm prosthesis, the mechanical model is divided in 2, one for the elbow and 1 for the shoulder, the thing is that everytime i try to simulate the agular position it gives me this error.

Error in default port dimensions function of S-function 'SimulacionPIA/MATLAB Function'. This function does not fully set the dimensions of output port 2

i cannot see why is failing so i could use some help.

The array im trying to use in the sources are 2 (2x1000) values

(Sorry for bad english is not my native language)

function [qpp1,qpp2] = r2dof(T1,T2,q1,q2,qp1,qp2)

qp=[qp1; qp2];
M=[.1935+.0494*cos(q)  .0371+.0090*cos(q2); .0180+.0090*cos(q2) .0180];

C=[-.05631*sen(q2)*qp2 -.0281*sen(q2)*qp2; .0281*sen(q2)*qp1 0.0];
 
parg=[.2815*sen(q1)+.3136*sen(q1)+.1005*sen(q1+q2); .1005*sen(q1+q2)];

fr=[1.86*qp1+1.93*sign(qp1); 0.16*qp2+0.3*sign(qp2)];

tau=[T1;T2];
qpp= M^(-1)*(tau-C*qp-parg-fr);
qpp1=qpp(1);
qpp2=qpp(2);

end