I was using Vim 7.4 with YCM quite successfully (thank you for YCM!) and just today noticed that Vim 8.0 was out. I downloaded, installed, started and now it complains that "YouCompleteMe unavailable:

requires VIM compiled with Python (2.6+ or 3.3+) support"

:version shows:


I am on Windows 10 and used the .exe installer. This was working before with 7.4, but not for 8.0.

Nothing else has changed. Python is on my path, and reports version 3.5.1


  • 5
    probably it could not load the python*.dll. First, check that your python installation is the same architecture (e.g. 32 vs 64 bit) as your vim installation, second I think it is best to simply throw the python*.dll into your vim installation path. Feb 3, 2017 at 6:45
  • I think should ask that on their issue tracker you'll be read by people actually developing/contributing to/using the plugin who will probably have a better knowledge of the plugin.
    – statox
    Feb 3, 2017 at 8:27
  • @ChristianBrabandt -- the version mismatch fixed it -- thanks! I had 32-bit VIM and 64 bit python. Installing the 64bit vim, fixed it. Feb 3, 2017 at 15:40

1 Answer 1


If your output from :version is to be believed you have vim build with both python2 and python3 support (dynamic). This will always trigger YCM to use the python 2 code paths. See the s:UsingPython2() function here which decides the path.

function! s:UsingPython2()
  " I'm willing to bet quite a bit that sooner or later, somebody will ask us to
  " make it configurable which version of Python we use.
  if has('python')
    return 1
  return 0

let s:using_python2 = s:UsingPython2()
let s:python_until_eof = s:using_python2 ? "python << EOF" : "python3 << EOF"
let s:python_command = s:using_python2 ? "py " : "py3 "

Removing the python 2 support should allow YCM to choose the correct version on its own.

  • thanks for the insight, but the problem was 32 v 64 bit. (I tried this first, but no luck). Thanks! Feb 3, 2017 at 15:42

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