AllFPF --> first ply failure analysis for the given load.
percload ---> stress and strain calculation for the given load
refer to example 4.2 and 4.3 in http://grad.iaumajlesi.ac.ir/index/images/stories/Courses/mavad-morakkab/mechanics_of_composite_materials_0849313430.pdf if you are unfamiliar with the theory
As for the possible error you might be getting in accessing the Excel file threw Matlab, make sure you copy the correct file directory of New Folder to both AllFPF (line 245) and in percload (line 11)
Example if you unzip the New Folder at the desktop, than line 245 and line 11 should be