How to fix “TF400898: An Internal Error Occurred.” on your Kanban board in TFS 2012 Update 2

This post addresses a specific provisioning error (TF400898) on the Kanban board in TFS 2012 Update 2 that occurs when customizable columns are enabled. The error arises from incorrect assumptions in the provisioning logic regarding the mapping of work item states to board columns, particularly when multiple states are mapped to the 'Complete' metastate or when different work item types within the Requirement category do not share the same last 'Complete' state. The post provides a detailed, step-by-step resolution using `witadmin` to export and modify category and common configuration XML files, followed by re-importing them to correct the provisioning. It also includes a workaround for persistent issues involving column renaming.