Hi raylai,
Thank you for the report. As of Knowage 8.1.2 categories are related to organizations, so we moved them from configurations to a new SBI_CATEGORY table. Also, we are working on creating a new GUI for user to manage them. It will be available soon in one of the future versions.
Meanwhile, if you need to add/remove one or more categories from Knowage, you should work on the SBI_CATEGORY table. Beware that for datasets you have to use "DATASET_CATEGORY" as category_type. Also, remember to set the correct value for the organization field.
Greetings
Alberto