Getting a sudden error on Magento backend / frontend

Question

Our webshop has been working fine for a while, today this error shows up on frontend:

There has been an error processing your request

Invalid backend model specified: ultramegamenu/category_attribute_backend_grid_columns

and this shows up in backend whenever I try to enter "category" menu item:

Source model "ultramegamenu/category_attribute_source_dropdown_type" not found for element "umm_dd_type"

It appears to be traces from an old theme that was installed on the server and present on the FTP, yet it was not enabled - I have removed all traces of the old theme in /app and /skin, and de-activated whatever modules remained that had relevance to it.

What could be causing this?

EDIT: Thank you for all your answers guys, but I figured it out with Adarsh! +1

Answer 1

If you want to delete/deactivate any extension, then first place to look at is etc/modules. You have to find corresponding file of extension and delete it.

Or simply open it and set <active>false</active>. This will make sure your extension is deleted/disabled.

However, if you store had some attribute related to this which is looks like your case, you will need to go to your database and find eav_attribute table and then find your attribute umm_dd_type in attribute_code column and delete it.

PS Before doing this please make backup of your database and files/folder

Answer 2

Go to database:

1) make a full backup

2) Run the query:

SELECT *
FROM `eav_attribute`
WHERE `backend_model` = 'ultramegamenu/category_attribute_backend_grid_columns';

3) remove found row

Answer 3

What this looks like is an extension, ultramegamenu, has added an attribute with a custom backend model. However, it seems that the extension either doesn't have the required class for the backend model, or has been removed or disabled so magento can't load the class. What I would do is look in your eav_attribute table for an attribute with that backend model and go from there.

If you don't need that attribute anymore you could simply remove the row, otherwise you need to debug why the class can't be found. Perhaps that extension has been removed or has been disabled in app/etc/modules

Answer 4

I hope umm_dd_type is a select or drop down category eav attribute.

Guess you have creating this attribute using installer.As you have creating dropdown and multi selection .As per as system ,you need add source model for this attribute which is save it option and label.

I hope ultramegamenu/category_attribute_source_dropdown_type” means(class ) does not define option and labels.So this error occurs.

Guss that this attribute may be create from a 3rd partly module.

You have remove this module or

this Attribute Source Class 3RdPartlyNameSpace_3RdPartlyModuleName_Model_Category_Attribute_Source_Dropdown_Type is missing from system.

For remove this error you need follow @Neklo.com answer.