When attempting to create a new Configurable product we get an incomplete screen for the Product Information i.e. just the left hand menu.
In the Apache error log we see
PHP Fatal error: Call to a member function getAttributeCode() on null in /var/www/vhosts/XXXXXXXXXX.co.uk/httpdocs/magento-126.96.36.199/app/code/core/Mage/Adminhtml/Block/Catalog/Product/Edit/Tab/Super/Config/Grid.php on line 245, referer: https://www.XXXXXXXXXXX.co.uk/index.php/cgb_mag_admin/catalog_product/new/set/79/type/configurable/key/7f90363b0508fd6c820a0f0ac01074ed/
The code in question reads in the product and gets a list of the attributes but they are empty of detail. I have created a brand new Attribute Set containing one brand new Attribute and used that to try and create but still fails.
This installation was built with an import of products from a 1.9.2 system. One can view the imported Configurable products and the Associated Products OK.
This installation was a copy up of code and database from a dev system here and it works fine in dev. I even copied the install back down again to test and it works so there must be some server issue but I cannot work out what it might be. Any help gratefully accepted.
PHP Version 5.6.36