Error when using make runoff

Hi

I use make_runoff to make a river file. After using this code, it shows my rivers properly. I can select the rivers and their directions. But in the end we have faced this error

Error using legend>process_inputs (line 564)
Invalid argument. Type ‘help legend’ for more information.

Error in legend>make_legend (line 327)
[orient,location,position,children,listen,strings,propargs] = process_inputs(ha,argin);

Error in legend (line 287)
[h,msg] = make_legend(ha,varargin(arg:end));

Error in make_runoff (line 684)
legend([h1,h3],{‘Approximative first guess river location’,‘final adjusted river
location’});

please guide me ith your interesting comments!!