EMClient V7 (7.0.26787.0) "Mark button" hangs EMClient when pressed on the Toolbar

If you customise the top toolbar in EMClient V7 Build 26787.0 and put the “Mark” button up there, EMClient hangs for aprox 5 secs when pressed before it does anything ?. So yes it does work, but its very delayed. Replicated this problem on 2 computers running Windows 10 Latest official build 1607. Ps This also happens with the “Categorize” Button on my other Forum Post.