Fix #376

plugin/cmp.lua

@@ -80,6 +80,7 @@ vim.cmd [[command! CmpStatus lua require('cmp').status()]]
 
 vim.cmd [[doautocmd <nomodeline> User cmp#ready]]
 
+if vim.on_key then
   vim.on_key(function(keys)
     if keys == vim.api.nvim_replace_termcodes('<C-c>', true, true, true) then
       vim.schedule(function()
@@ -89,4 +90,5 @@ vim.on_key(function(keys)
       end)
     end
   end, vim.api.nvim_create_namespace('cmp.plugin'))
+end