@irfyr Are you starting from your Inbox or your Profile Page? You need to be at your Inbox to start a conversation. Click on Inbox next to your username in the upper-right of the page. That will open your Conversations. Then again in the upper-right (slightly below the username area) should be a button "Start a New Conversation" -- on my screen it's a blue button at the end of the gray bar, but I don't know if that changes based on the color scheme you are using. As a note, if the person you wish to PM does not yet have 10 posts, you won't be able to do the Conversation.