Some of you may be familiar with the “You are already moving” message, this has now been replaced with “The previous action has not yet completed” which is more generic but can be applied to other situations such as the Tracking system.
The message basically means that the last thing you clicked on has not yet finished running so you can not do something else until it has finished.
Although with the new message comes a clickable “Cancel Action” link that will reset the previous action and let you choose to do something else, which could previously be accomplished by clicking the green Refresh button (which will still work).