I wish to forward a whatsapp conversation as an email from Blackberry Passport

I was on chats Overview Window. From there, I tap and hold the chat Which I want to send by email. A menu on the right side popped up, giving me the option of forwarding the chat by email. When I tap on the option of forwarding the chat by email, it directed me for adding an email ID. After adding the email ID, it is not providing any option of forwarding the chat.

I thought I did some mistake in adding the email, so I tried to repeat the same process again, but could not succeed as the email ID was already added there.

So Please help me in forwarding a whatsapp conversation as an email from Blackberry Passport