Add Features to Existing MVC Project

In progress MVC inventory tracking project, implement the following features 1) Multiple selection dropdown List for Product Vendors. Implement CRUD operation for Product. 2) Implement File upload feature on Products Controller. 3)Resolve following error "Error activating IBASE_FileAttachmentRepository using binding from IBASE_FileAttachmentRepository to IBASE_FileAttachmentRepository No constructor was available to create an instance of the implementation type."