diff --git a/autoload/SpaceVim/autocmds.vim b/autoload/SpaceVim/autocmds.vim
index 25be7d112..015324b86 100644
--- a/autoload/SpaceVim/autocmds.vim
+++ b/autoload/SpaceVim/autocmds.vim
@@ -60,6 +60,7 @@ function! SpaceVim#autocmds#init() abort
       autocmd FocusLost * call system('synclient touchpadoff=0')
       autocmd FocusGained * call s:reload_touchpad_status()
     endif
+    " @fixme this autocmd should also support `:w foo/test.vim`
     autocmd BufWritePre * call SpaceVim#plugins#mkdir#CreateCurrent()
     autocmd ColorScheme * call SpaceVim#api#import('vim#highlight').hide_in_normal('EndOfBuffer')
     autocmd ColorScheme gruvbox,jellybeans,nord,srcery,NeoSolarized call s:fix_colorschem_in_SpaceVim()
diff --git a/autoload/SpaceVim/layers/autocomplete.vim b/autoload/SpaceVim/layers/autocomplete.vim
index 9d26dd880..14bdcccef 100644
--- a/autoload/SpaceVim/layers/autocomplete.vim
+++ b/autoload/SpaceVim/layers/autocomplete.vim
@@ -126,7 +126,7 @@ endfunction
 
 function! SpaceVim#layers#autocomplete#config() abort
   if g:spacevim_autocomplete_parens
-    imap <expr>(
+    imap <expr> (
           \ pumvisible() ?
           \ has('patch-7.4.744') ?
           \ complete_parameter#pre_complete("()") : '(' :
diff --git a/autoload/SpaceVim/layers/core.vim b/autoload/SpaceVim/layers/core.vim
index c09c3a103..976a6a1f9 100644
--- a/autoload/SpaceVim/layers/core.vim
+++ b/autoload/SpaceVim/layers/core.vim
@@ -939,6 +939,18 @@ function! s:save_current_file() abort
   endif
 endfunction
 
+
+" the `SPC f a` key binding cause many erros:
+" E212: Can't open file for writing: no such file or directory
+" E216: No such group or event: FileExplorer
+"
+" Fix E216: No such group or event: FileExplorer
+" which is called in bundle/nerdtree/plugin/NERD_tree.vim:184
+augroup FileExplorer
+  autocmd!
+augroup END
+
+
 function! s:save_as_new_file() abort
   let current_fname = bufname()
   if !empty(current_fname)
diff --git a/bundle/delimitMate/plugin/delimitMate.vim b/bundle/delimitMate/plugin/delimitMate.vim
index cf16fe84c..20c614b68 100644
--- a/bundle/delimitMate/plugin/delimitMate.vim
+++ b/bundle/delimitMate/plugin/delimitMate.vim
@@ -275,7 +275,7 @@ function! s:NoAutoClose() "{{{
       let delim = '<Bar>'
     endif
     exec 'inoremap <silent> <Plug>delimitMate' . delim . ' <C-R>=<SID>TriggerAbb().delimitMate#SkipDelim("' . escape(delim,'"') . '")<CR>'
-    exec 'silent! imap <unique> <buffer> '.delim.' <Plug>delimitMate'.delim
+    exec 'silent! imap <buffer> '.delim.' <Plug>delimitMate'.delim
   endfor
 endfunction "}}}
 
@@ -288,7 +288,7 @@ function! s:AutoClose() "{{{
     let rd = s:get('right_delims')[i] == '|' ? '<bar>' : s:get('right_delims')[i]
     exec 'inoremap <expr><silent> <Plug>delimitMate' . ld
                 \. ' <SID>TriggerAbb().delimitMate#ParenDelim("' . escape(rd, '|') . '")'
-    exec 'silent! imap <unique> <buffer> '.ld
+    exec 'silent! imap <buffer> '.ld
                 \.' <Plug>delimitMate'.ld
     let i += 1
   endwhile
@@ -298,7 +298,7 @@ function! s:AutoClose() "{{{
     let delim = delim == '|' ? '<bar>' : delim
     exec 'inoremap <expr><silent> <Plug>delimitMate' . delim
                 \. ' <SID>TriggerAbb().delimitMate#JumpOut("\' . delim . '")'
-    exec 'silent! imap <unique> <buffer> ' . delim
+    exec 'silent! imap <buffer> ' . delim
                 \. ' <Plug>delimitMate'. delim
   endfor
 
@@ -310,7 +310,7 @@ function! s:AutoClose() "{{{
     endif
     exec 'inoremap <expr><silent> <Plug>delimitMate' . delim
                 \. ' <SID>TriggerAbb()."<C-R>=delimitMate#QuoteDelim(\"\\\' . delim . '\")<CR>"'
-    exec 'silent! imap <unique> <buffer> ' . delim
+    exec 'silent! imap <buffer> ' . delim
                 \. ' <Plug>delimitMate' . delim
   endfor
 
@@ -318,7 +318,7 @@ function! s:AutoClose() "{{{
   " inoremap <silent> <buffer> n't n't
   for map in s:get('apostrophes_list')
     exec "inoremap <silent> " . map . " " . map
-    exec 'silent! imap <unique> <buffer> ' . map . ' <Plug>delimitMate' . map
+    exec 'silent! imap <buffer> ' . map . ' <Plug>delimitMate' . map
   endfor
 endfunction "}}}
 
@@ -327,31 +327,31 @@ function! s:ExtraMappings() "{{{
   inoremap <silent> <Plug>delimitMateBS <C-R>=delimitMate#BS()<CR>
   if !hasmapto('<Plug>delimitMateBS','i')
     if empty(maparg('<BS>', 'i'))
-      silent! imap <unique> <buffer> <BS> <Plug>delimitMateBS
+      silent! imap <buffer> <BS> <Plug>delimitMateBS
     endif
     if empty(maparg('<C-H>', 'i'))
-      silent! imap <unique> <buffer> <C-h> <Plug>delimitMateBS
+      silent! imap <buffer> <C-h> <Plug>delimitMateBS
     endif
   endif
   " If pair is empty, delete closing delimiter:
   inoremap <silent> <expr> <Plug>delimitMateS-BS delimitMate#WithinEmptyPair() ? "\<Del>" : "\<S-BS>"
   if !hasmapto('<Plug>delimitMateS-BS','i') && maparg('<S-BS>', 'i') == ''
-    silent! imap <unique> <buffer> <S-BS> <Plug>delimitMateS-BS
+    silent! imap <buffer> <S-BS> <Plug>delimitMateS-BS
   endif
   " Expand return if inside an empty pair:
   inoremap <expr><silent> <Plug>delimitMateCR <SID>TriggerAbb()."\<C-R>=delimitMate#ExpandReturn()\<CR>"
   if s:get('expand_cr') && !hasmapto('<Plug>delimitMateCR', 'i') && maparg('<CR>', 'i') == ''
-    silent! imap <unique> <buffer> <CR> <Plug>delimitMateCR
+    silent! imap <buffer> <CR> <Plug>delimitMateCR
   endif
   " Expand space if inside an empty pair:
   inoremap <expr><silent> <Plug>delimitMateSpace <SID>TriggerAbb()."\<C-R>=delimitMate#ExpandSpace()\<CR>"
   if s:get('expand_space') && !hasmapto('<Plug>delimitMateSpace', 'i') && maparg('<Space>', 'i') == ''
-    silent! imap <unique> <buffer> <Space> <Plug>delimitMateSpace
+    silent! imap <buffer> <Space> <Plug>delimitMateSpace
   endif
   " Jump over any delimiter:
   inoremap <expr><silent> <Plug>delimitMateS-Tab <SID>TriggerAbb()."\<C-R>=delimitMate#JumpAny()\<CR>"
   if s:get('tab2exit') && !hasmapto('<Plug>delimitMateS-Tab', 'i') && maparg('<S-Tab>', 'i') == ''
-    silent! imap <unique> <buffer> <S-Tab> <Plug>delimitMateS-Tab
+    silent! imap <buffer> <S-Tab> <Plug>delimitMateS-Tab
   endif
   " Jump over next delimiters
   inoremap <expr><buffer> <Plug>delimitMateJumpMany <SID>TriggerAbb()."\<C-R>=delimitMate#JumpMany()\<CR>"