In your TabbedOSRBrowser demo, ShowBrowser procedure is written as
If the statement “chrmosr.WasResized;” is removed, the calling to wasHidden(false) will fail if too many tabs are opened. It's something like old version which needs to resize by 1 pixel after calling to wasHidden(false) .procedure TBrowserFrame.ShowBrowser;
begin
if chrmosr.Initialized and not(FTabVisible) then
begin
chrmosr.WasHidden(False);
chrmosr.WasResized;
chrmosr.SetFocus(True);
FTabVisible := True;
end;
end;