If you add a task in blank, with out nothing, don't validate and accept that...
Please tell me - what browser are you using and can you reproduce this issue in a different browser?
I can't trigger it at all, neither from within a project nor through the Quick Add feature. Trying to add an empty task does nothing.
Please describe step-by-step what exact actions you perform to trigger this issue as I can't reproduce this. Incl. as many details as you can - on what view are you, what keyboard shortcuts do you use (if any) etc.