elixir-ls fails to start about coc-elixir HOT 2 CLOSED

Whether I use the built-in version of elixir-ls or I build it on my own, the :CocInfo after opening an .exs or .ex file shows the following:

15:10:53.029 [info]  Application forms exited: :stopped
Elixir version: "1.10.3 (compiled with Erlang/OTP 21)"
Erlang version: "23"

I just fixed my coc-elixir today after upgrading to 0.5.0, I had an error similar to yours.
Turns out the ElixirLS release files were all compiled with OTP 23, but my current workspace is set to use OTP 22.

So I had to re-compile ElixirLS using my env. Maybe the same will work for you.

from coc-elixir.

I seem to have solved it by recompiling everything under OTP 20, installing the correct versions with asdf. Not ideal, but for a beginner doesn't really mean much.

Thanks for your help!

from coc-elixir.