Errors about function names

[khalidchawtany]

I am a newbie at vimscript and I cannot get this plugin to work. I get a lot of error messages about function names cannot start with b: or lowercase letters.

This error is shown when I open a vim file:

Error detected while processing /Volumes/Home/.config/nvim/plugged/vim-hopper/ftplugin/vim.vim:
line    1:
E128: Function name must start with a capital or "s:": b:load_hopper_by_filetype()
line    4:
E193: :endfunction not inside a function
line    1:
E128: Function name must start with a capital or "s:": b:load_hopper_by_filetype()
line    4:
E193: :endfunction not inside a function
Error detected while processing function hopper#load_movement_mode:
line    4:
E884: Function name cannot contain a colon: b:load_hopper_by_filetype()