Fixed it.

There were 2 typos in the file AEmisss_fast_skin_mayaTemplate.mel
The word 'Simple' had to be replaced with the word 'Skin'.

This section in the text editable file

// bump
editorTemplate -beginLayout (uiRes("m_AEmisss_fast_skin_mayaTemplate.kBumpShad er")) -collapse 1;
editorTemplate -callCustom "AEmisssSimpleMayaBumpNew" "AEmisssSimpleMayaBumpReplace" "normalCamera";
editorTemplate -endLayout;

should read

// bump
editorTemplate -beginLayout (uiRes("m_AEmisss_fast_skin_mayaTemplate.kBumpShad er")) -collapse 1;
editorTemplate -callCustom "AEmisssSkinMayaBumpNew" "AEmisssSkinMayaBumpReplace" "normalCamera";
editorTemplate -endLayout;

Working fine now.