NullReferenceException on calling AutoSaveData() function.

[fundoozzz]

I am getting this error " NullReferenceException: Object reference not set to an instance of an object
AutoSave.AutoSaveData () (at Assets/Scripts/Managers/AutoSave.cs:185)
AutoSave.Update () (at Assets/Scripts/Managers/AutoSave.cs:108)"

when i try to call AutoSaveData() from within the script.
I have tried the sample scene and instead of calling OnSave() from Save button, i called AutoSaveData() and I am getting the said exception.