as I move cursor to those word of blue and yellow mark
there is no hint pop-up as usual.
Try clicking on the words to see if the popup appears. Also, try refreshing the page to see if that helps. If you still experience this problem, please let us know.
it works, thanks
Great! Please let us know if you have any more problems in the future 
Hi, I am having a similar problem. I just got a new PC and am not getting the hints over blue and yellow words, either. Clicking them does not work. Any solution?
Since your setting may be set to “hover”, try leaving your mouse cursor over a blue word for a second or two and see if it works. You can also change your popup settings so that the yellow popups open on a click. This setting is found on the bottom of the Settings page.
I just tried both suggestions. It still does not work.
What browser are you using? Do you notice the same problem when you try another browser?
Firefox, and yes I tried using Internet Explorer as well.
We’re actively working on another bug that may be related to the issues you are experiencing. Please give us some time as we get it sorted out. It hopefully won’t take too long
We just pushed a fix so would you mind refreshing the page and trying again? Please let us know if the errors persist. Also, if you are using Internet Explorer can you tell us if there are any Javascript errors on the page? Simply look at the status bar at the bottom and it will tell you.
Seems to have been related to Javascript on Firefox. I fixed it by disabling the checked boxes for Javascript in the settings.
Great to hear Do let us know if you encounter any other problems!