mouse_renameShaders 1.1.0 for Maya (maya script)

i am using maya 2015 the error is occur and list below:

spM_renameShaders.spM_renameShaders()Renaming shader "testLambert_mat"'s network with prefix "testLambert"-Evaluating name for shading node: "file50"# Error: TypeError: file C:/Users/ChrisWong/Documents/maya/scripts\spM_renameShaders.py line 123: 'NoneType' object is not iterable #