vim安装YouCompleteMe失败

Question

win10系统，
vim是从这里下载的64位的：
Vim 8.1.0547适用于Windows
YouCompleteMe是按照github上的完整安装指南安装，所有步骤也都成功了。
打开Vim后提示（编译ycm_core之前打开Vim也是报这个错误）：

YouCompleteMe unavailable: 'utf-8' codec can't decode byte 0xbc in position 9: i
nvalid start byte
Messages maintainer: Bram Moolenaar <[e-mail]>
Traceback (most recent call last):
  File "<string>", line 35, in <module>
  File "C:\Users\XXX\.vim\bundle\YouCompleteMe\python\ycm\base.py", line 25, in
 <module>
    from ycm import vimsupport
  File "C:\Users\XXX\.vim\bundle\YouCompleteMe\python\ycm\vimsupport.py", line
25, in <module>
    from future.utils import iterkeys
  File "C:\Users\XXX\.vim\bundle\YouCompleteMe\third_party\ycmd\third_party\pyt
hon-future\src\future\utils\__init__.py", line 54, in <module>
    import copy
  File "E:\develop\Python37\Lib\copy.py", line 60, in <module>
    from org.python.core import PyStringMap
  File "<frozen importlib._bootstrap>", line 983, in _find_and_load
  File "<frozen importlib._bootstrap>", line 963, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 906, in _find_spec
  File "<frozen importlib._bootstrap_external>", line 1280, in find_spec
  File "<frozen importlib._bootstrap_external>", line 1252, in _get_spec
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xbc in position 9: invalid
start byte    

配置文件：

set encoding=utf-8
set nocompatible
filetype off

set rtp+=~/.vim/bundle/Vundle.vim
call vundle#begin()

Plugin 'VundleVim/Vundle.vim'
Plugin 'vim-airline/vim-airline'
Plugin 'mattn/emmet-vim'
Plugin 'Valloric/YouCompleteMe'

call vundle#end()
filetype plugin indent on

跪求解答，谢谢。