Only `Connected` shows in the new tab

[qqlovekerry]

Hello, I followed the instructions and copied the file md_instant.vim and folder md_instant into ~/.vim/plugin. But when I type :Instantmd in vim, only

Connected

shown in the newly opened tab. Did I miss something? How can I fix this?
By the way, I did not install vim-markdown. And I installed vim latex-suite before.
Any help would be much appreciated!