No reply button problem

Some postings that I want to reply to have no reply button.  Also the reply button at the beginning of the thread is faded/non-working.  This is my first attempt to reply on this forum, and I don't understand why the reply is not working.  Is this a bug or am I missing something?

Some postings that I want to reply to have no reply button.  Also the reply button at the beginning of the thread is faded/non-working.  This is my first attempt to reply on this forum, and I don't understand why the reply is not working.  Is this a bug or am I missing something?