Your first mistake was to modify Acad####Doc.lsp (in your case Acad2013Doc.lsp), which is an AutoCAD Owned file that can be overwritten during an Update without notification.
Autoload is a LISP function that is included within Acad####Doc.lsp, which suggests that your Autoload statements are being called prior to Autoload even being defined... prompting the error you're currently receiving.
Any/all custom, corporate, or internal LISP loading should be included within the User Owned files Acad.lsp, AcadDoc.lsp, or [YourEnterpriseCuixFileName].mnl only. Each has it's own purpose, and will persist during an Update.
If the needed file(s) do not exists, simply create them, and store them in the top file path in your Support File Search Paths (SFSP).