This error can occur if you have installed Simulink Response Optimization 3.1 (R2006b) but do no possess the license. To verify your license for Simulink Response Optimization please type the following command in the MATLAB command window:
which -all optimset
This will find all instances of the function OPTIMSET in your MATLAB Path. Most probably this command will output multiple lines, each line corresponds to one found instance of the function. If Simulink Response Optimization is installed but not correctly licensed one of the lines will read:\n
$MATLABROOT\toolbox\sloptim\sloptim\@ResponseOptimizer\simset.m % ResponseOptimizer method, Has no license available
(Where $MATLABROOT is the base installation directory of MATLAB as returned by typing 'matlabroot' in the MATLAB command window.)
If the product is not correctly licensed, please obtain and install a valid license.
If you find this line without "Has no license available" then Simulink Response Optimization is correclty installed and licensed. In this case the error message is not caused by any licensing issue. In this case, following steps have proven to resolve the issue for few users:
(1) Please verify whether the necessary requirements are installed on the machine