gistfile1.txt

diff --git a/plugin/bufexplorer.vim b/plugin/bufexplorer.vim
index 8791363..6024bf7 100644
--- a/plugin/bufexplorer.vim
+++ b/plugin/bufexplorer.vim
@@ -183,7 +183,10 @@ function! s:BEActivateBuffer()
   elseif empty(l) || index(l, b) == -1
     " Add new buffer to this tab buffer list
     let l = add(l, b)
-    let s:tabSpace[tabpagenr()] = l
+
+    " note: it will be out of range
+    " original solution: let s:tabSpace[tabpagenr()] = l
+    call add(s:tabSpace, l )
 
     if g:bufExplorerOnlyOneTab == 1
       " If a buffer can only be available in 1 tab page

This solve the problem detected while processing function <SNR>63_BEActivateBuffer, Thanks.