Autocomplete error

Hi Jordan,
I'm a newbie in Vim/MacVim. I installed the VimBox and started to use it as-is. I was editing a python file in insert mode when I received the error message:
Error: Required Vim compiled with +python
E117 Unknown function: pythoncomplete#Complete
Press Enter or type ...

I'm using a MacOs HighSierra with python 3.6.3 installed via Homebrew and python 2.7.12 in the System. The MacVim installed was compiled with -python & +python3
Note that I only use python3 in my projects. I don't know how to fix this issue, so I commented the lines in the file ~/VimBox/dotVim/bundlesVimRc:
Plug lifepillar/vim-mucomplete'
source ~/.vim/pluginRc/mucompleteVimRc

Any help is very welcome. I really liked VimBox!
Tks in advance,
Marcio

The report points to ~/VimBox/dotVim/bundlesVimRc and ~/.vim/pluginRc/mucompleteVimRc; start by reviewing those entries and the reported MacVim +python/-python3 build details. Reproduce the autocomplete failure with the stated Python 3 setup, then confirm that the error is resolved or that the required compatibility and configuration are documented.

Written by the indexing model from the issue text.