I was in the process of following a tutorial showing how to make a module on my dev machine. The module didn't work for me so I decided to remove all files relating to it. Now i'm getting the following error: Still scratching my head over this as I can't find anything relating to it! Any ideas please?

<b>Fatal error</b>:  Class 'Mage_Newslettersubscribe_Helper_Data' not found in <b>C:\xampp\htdocs\magento\app\Mage.php</b> on line <b>547</b><br />
  • Try to search in your code the string like Mage::helper('newslettersubscribe') or just newslettersubscribe, maybe you added this code somewhere in the templates. Mar 27, 2018 at 11:01
  • Thank you Siarhey - I've searched file names, file content and database and can't find anything! - deleted the cache files too. Got me stumped.
    – Andy
    Mar 27, 2018 at 12:03

1 Answer 1


The problem most probably resides in your layout xml for the update or for a translation of a string in your template. The module Mage_Newslettersubscribe seems not to exists with 1.9 (I am checking on my machine but I am almost sure). If it does not exists either on yours, then try to look for the module that implements this helper and remove it. You can use debug_print_backtrace(2) in Mage.php line 547 to see where is that called. The option for debug_print_backtrace is really important has a lot of data can be passed as arguments.

To go further :

  • Magento first tries to find the helper defined like that in any of the configuration of modules (first in local, then in community, then in core). The normal way is to call helpers like mycompany/mymodule but some does not follow this rule. In some cases the fallback goes to magento modules themselves and if it still does not exists, it crashes.
  • The problem can also occurs using the $this->__('translation of string') in a template. Magento will try to find out what this stands for using the previously described fallback system. For example, if you have a block called newslettersuscrbe/typeofblock.
  • Eventually, it can happen to be a windows naming problem as it looks like that you use windows. Windows is not case sensitive by default therefore it can work on your machine but not on the server (it is not your case at the moment but I tell that it happens)
  • Thanks to all......I ended up overwriting my local app folder with the live version. Simply could not find the problem!
    – Andy
    Mar 28, 2018 at 15:18

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