There's something wrong with creating posts on forum

If I try to make a post with the following content::

[The new Bootstrap is out][1], but it's still in alpha. Do you plan to support it?
  // [1]: https://v5.getbootstrap.com/

It's a success. However, when I try to insert the image:

![enter image description here][1] // [1]: https://i.imgur.com/N4wapq4.png

Then I can't open the post. (You cannot reply to this topic.)

p.s Two brackets are added so that you can see the code I'm inserting in this post.

Example url: https://bootstrapstudio.io/forums/?post_type=topic&p=19206

Testing on iPad

EDIT: works for me.