Hi Jason,
Do you have other Matlab toolboxes installed on your computer?
Make sure that you don’t have any function that shadows the original Matlab functions firls.m and fir1.m in your path.
In your Matlab command window, type “which firls” and “which fir1”. This shows the path from which the functions are executed. If any of the path is not in your Matlab Signal Processing Toolbox installation folder (eg. …/MATLAB/R2014b/toolbox/signal/signal/), there is something wrong with your path. Remove the corresponding path from your Matlab path and try again.
Cheers,
Francois