Invalid workspace data format for root Inport, please help me. thanks.

Hi, I have used NNCTRL20 Toolbox fonction (apccon.m), I used Simulink model, I have obtained error in matlab command.

 >>>>>>>>>>>>>>>>>>>>>>>>    READ OUTPUT FROM PLANT     <<<<<<<<<<<<<<<<<<<<<

 >> if strcmp(simul,'simulink')
 >> utmp=[t-Ts,u_old(1);t,u_old(1)];
 >> simoptions.InitialState=x0;
 >> [time,x0,y] = sim(sim_model,[t-Ts t],simoptions,utmp); ** ERROR (line 132) **
 >> x0 = x0(size(x0,1),:)';
 >> y  = y(size(y,1),:)';

Error using apccon (line 132) Invalid workspace data format for root Inport 'Model/Inport'. The model is configured to load its root level ports from the workspace. The workspace data specified for this root Inport is a column vector; you should use that format only with a root Inport that outputs a function-call signal. Use one of these approaches: a) For the workspace data to be loaded, use a format other than a column vector; b) For this root Inport, select the 'Output function call' block parameter; or c) Turn off loading of external inputs by clearing the Configuration Parameters -> Data Import/Export -> Input parameter.

So can anyone please help me ascertain what's going wrong and how I can fix this issue? thanks.