I was able to solve this accidentally with the help of others while working on a different problem. I’m running on a Mac, which uses LibreSSL 3.3.6 instead of the regular openssl. This was causing the crypto module to be ignored when I installed erlang via asdf. The solution was to use Homebrew to install openssl, then tell KERL (which asdf uses) to use this version of openssl:

export KERL_CONFIGURE_OPTIONS="--without-javac --with-ssl=$(brew --prefix openssl@3"

Then I reinstalled erlang via asdf and all is well now. The crypto module is no longer ignored during erlang installation and I can use the latest version of ElixirLS with no problem.

I just fixed this on my Windows WSL Ubuntu setup.

TL;DR
What I did:
sudo apt remove elixir
sudo apt-get install libssl-dev
asdf plugin-add erlang
asdf plugin-add elixir
asdf install erlang 26.1.1
asdf install elixir 1.15.6-otp-26
asdf global erlang 26.1.1
asdf global elixir 1.15.6-otp-26

Basically, the sudo apt approach is broken. The way to test it is to git clone the ElixirLS repo and try to compile it.

mix deps.get and then mix compile

If this works, there’s good bet that VSCode doing the same thing (compiling ElixirLS) will work and connect.

I removed the elixir install and reinstalled using the embedded elixir approach. - however there is a dependency (documented here: [WSL - mix deps.get] The application "crypto" could not be found - #9 by thelucassampaio) - which is that you need to install libssl first and then use asdf to install-compile erlang and then elixir.

If this worked then the ElixirLS you cloned into a folder should compile. If not, see what error you are getting and go search - this is how I worked my way through this.

Only took 4 hours

It may not be the “correct” approach but at least it’s working for me now.