How to insert discussion or document by line [RESOLVED]

When I try to insert discussion or document by line . I get the blank popup .I have enabled the discussions in site setup.

I have attached the screen shots below

Is this a new question?
If so: please dont put it in the same thread (but another).

You might want to ask some of the questions on #plone chat. There is a link at (at the bottom)

@AnanthaBalaji, is this Plone 5.1.2 (the latest version)? Which browser are you using? And have you changed anything else on the Plone site before running into this issue?

No I installed Mosaic and then tried to insert. It comes as blank

This happened when I am using Mosaic

For us to be able to help you, please answer these questions ^^^ Also, what instructions did you follow to install Mosaic (and which versions of Mosaic and its dependencies)?

Now I rectified the error , It had problem with the content type we used