I'm going through the process of upgrading all sites using the old CMS plugin to the latest MCB plugin. One of the sites now has the Custom Blocks visible as well as the same information in Custom Fields. The Custom fields are entitled the same as the MCB areas but preceded with the letters 'mcb-'. The Custom fields cannot be deleted.
I have one more site to do in the CMS to MCB transfer. I have left it until last as it has a large amount of data in Content Blocks.
Any ideas on a fix before I attempt the big one?