Cannot post on forums via iPhone

[hajime]

Hello, I visited some forums including macrumors. When I hit the reply button, the text box appeared but the virtual keyboard did not show up even I touched the the text editing box. Know what is wrong?

 

[Michael Anthony]

What hardware and system are you running?

 

[hajime]

iPhone 6s Plus with the version before iOS 10. With iOS 10, I can post now. Thanks