I'm running into the darnedest thing on a drawing - I've added a revision in a standard SolidWorks revision table, and it won't allow me to add a corresponding symbol. When I right click on the row in the table and get the drop-down, the "Revision" fly-out only has the selection to add another revision, rather than add a revision symbol as well. When I use the menu to perform an Insert > Annotations > Revision Symbol, the "Revision Symbol" menu item is grayed out. It's really infuriating.
I have no trouble with other drawings, doing the same thing. It's our standard border & title block, and as I said, I'm using a standard SolidWorks revision table.