These are some images describe this problem.
Figure 1: When you select a text or a paragraph, and try to drag it
part1.jpg
Figure 2: The computer becomes to non-responding. There is a gray background appearing behind the "dragged" text.
part2.jpg
Figure 3: Another picture after figure 2
part3.jpg
This is a light case, when I just try to drag a small text. The system will not respond a little time, about 30 seconds. But when you drag a larger text, above 5 lines, I don't know when the system restore like before. So I just turn off my computer by the power button.

This is my os infomation:

$ uname -a
Linux kali 4.6.0-kali1-amd64 #1 SMP Debian 4.6.4-1kali1 (2016-07-21) x86_64 GNU/Linux
$ lsb_release -a
No LSB modules are available.
Distributor ID: Kali
Description: Kali GNU/Linux Rolling
Release: kali-rolling
Codename: kali-rolling