Uncaught TypeError: Cannot read property 'className' of null

[SuperMarioSF]

1. Open multiple panel of pane-browser;
2. Close them one by one;
3. When you closed all pane-browser, it thown things below.

Atom: 1.16.0 x64
Electron: 1.3.13
OS: Microsoft Windows 7 SP1 (NT6.1)
Thrown From: pane-browser package 1.6.0

Stack Trace

Uncaught TypeError: Cannot read property 'className' of null

At C:\Users\SuperMarioSF\.atom\packages\pane-browser\node_modules\nprogress\nprogress.js:463

TypeError: Cannot read property 'className' of null
    at classList (/packages/pane-browser/node_modules/nprogress/nprogress.js:463:27)
    at addClass (/packages/pane-browser/node_modules/nprogress/nprogress.js:430:19)
    at Object.NProgress.render (/packages/pane-browser/node_modules/nprogress/nprogress.js:244:7)
    at Object.NProgress.set (/packages/pane-browser/node_modules/nprogress/nprogress.js:70:30)
    at Object.NProgress.inc (/packages/pane-browser/node_modules/nprogress/nprogress.js:170:24)
    at Object.NProgress.trickle (/packages/pane-browser/node_modules/nprogress/nprogress.js:175:22)
    at /packages/pane-browser/node_modules/nprogress/nprogress.js:127:19

Commands

     -0:27.9.0 Pane Browser: Open (input.hidden-input)
  2x -0:23.1.0 pane:close (div#atom-pane-browser__webview-wrapper.nprogress-custom-parent)

Non-Core Packages

atom-autocomplete-php 0.22.2 
atom-beautify 0.29.23 
atom-clock 0.1.7 
atom-commander 0.9.0 
atom-html-preview 0.1.22 
autocomplete-bash-builtins 0.3.5 
autocomplete-python 1.8.63 
cson 2.0.1 
pane-browser 1.6.0 
python-debugger 0.2.0 
python-tools 0.6.9 
simplified-chinese-menu 5.3.1 
termination 0.5.1