Was about to say, it's a blank ad banner. I get more ads than content in terms of surface area, and that top one is always there. I take it on the chin as I haven't become a paid supporter yet, but may reconsider as it's gone from occasional ad inserted between posts, to all of a sudden a full page popup ad that needs to be dismissed after every click, as well as the permanent tab banner at the top. It's not a change of the forum page, it's all ad overlays, so probably nothing admin can change and probably just needs subscription status.