Problem with adding Custom Reports on Report Dashboard

Content

Hello

I'm using February 2016, and I've been trying to add two custom reports on Report Dashboard, referring to the following Answer;

https://cx.rightnow.com/app/answers/detail/a_id/2447

It worked in the middle of the last week. Actually adding new Custom Reports is very easy, just drag and drop the reports from Report Analysis Pane. However when I tried the same procedure on newly created Report Dashboard or modifying the existing Report Dashboard, "drag and drop" didn't work any longer. I'm attaching the screenshot to show you what is happening on my Report Dashboard.

Version

February 2016