Remove the footer, that was probably accidentally created.

F.A.Q..md

@@ -29,4 +29,15 @@ Use the `t` and `T` mappings in the NERDTree window.
 ## How can I close NERDTree window after opening a file from it?
 Use this NERDTree setting: `let NERDTreeQuitOnOpen = 1`. However if you usually want NERDTree to stay open, but sometimes want it to close after opening a file, you can use one of these option.
 1. Use the NERDTree keys: `go` followed by `q`.
-1. You can map another key to do `goq` for you: `autocmd FileType nerdtree nmap d goq`
+1. You can map another key to do `goq` for you: `autocmd FileType nerdtree nmap d goq`
+
+## How can I make sure vim does not open files and other buffers on NerdTree window?
+
+```vim
+" If more than one window and previous buffer was NERDTree, go back to it.
+autocmd BufEnter * if bufname('#') =~# "^NERD_tree_" && winnr('$') > 1 | b# | endif
+```
+If you are using vim-plug, you'll also need to add these lines to avoid crashes when calling vim-plug functions while the cursor is on the NERDTree window: 
+```vim
+let g:plug_window = 'noautocmd vertical topleft new'
+```