Fix

Author: Shougo

autoload/dein.vim

@@ -61,8 +61,7 @@ function! dein#direct_install(repo, options = {}) abort
   call dein#install#_direct_install(a:repo, a:options)
 endfunction
 function! dein#get_direct_plugins_path() abort
-  return dein#util#_get_cache_path()
-        \ .'/direct_install.vim'
+  return dein#util#_get_cache_path() .. '/direct_install.vim'
 endfunction
 function! dein#reinstall(plugins) abort
   call dein#install#_reinstall(a:plugins)

doc/dein.txt

@@ -517,12 +517,12 @@ g:dein#cache_directory
 		Default: Under the base directory you have already specified
 		by |dein#begin()|.
 
-                                                      *g:dein#runtime_directory*
+                                                    *g:dein#runtime_directory*
 g:dein#runtime_directory
-		The runtime directory to use. Contains all merged files.
+		The runtime directory to use. It contains all merged files.
 		See |dein-merge| notes.
 
-		Default: |g:dein#cache_directory| . '/.dein'
+		Default: |g:dein#cache_directory| .. '/.dein'
 
                                                       *g:dein#default_options*
 g:dein#default_options