I am creating several new configurable products in Magento 1.9 using a few different attributes for each one.
Each of the attributes has been created in the same way. Each of the simple products and configurable products have been created in the same way.
For some of the products, I can click on the 'select all' checkbox after filtering to display the products I want to associate. For others, the checkbox is greyed out and if I inspect the element I can see it is set to disabled=disabled.
What is causing some of the checkboxes to be disabled?
The checkbox is disabled for those products no matter if I choose to show 'Yes' only products that are associated, 'No' only products that are not associated, or 'Any' products that are and are not associated.
Any ideas as to what could cause the checkbox to be disabled?