When Creating New Categories it won't let me move the forums I want to organize into the newly created category fields.

In the Organize Forums overview, you should be able to drag and drop forums between the different forum groups (for example from IC to OOC). There is a drag-and-drop handle on the right (diagonally marked area).

When you create a new group (button at the bottom) you can choose a name for the new group and you should be able to drag and drop forums into the new group.

If this does not work, could you elaborate on what you are doing, what you expected should have happened and what happened instead, so we can narrow down the problem? It'd also be helpful to know what browser you are using (and if you are on a mobile device, what type of device, i.e. Android, iPhone, etc)

Since we've not heard anything for a while, I'm assuming that Mercury's explanation helped the solve the issue. I'm marking it as Resolved.

(If not, please feel free to continue in this thread, and I'll unmark it)