Could not find package elm-lang/core

[sea-witch]

I follow the instructions:

git clone https://github.com/evancz/elm-architecture-tutorial.git
cd elm-architecture-tutorial
elm-reactor

The dev server runs and the home page loads fine. But when I go to an example, I see an error. For instance, http://localhost:8000/examples/01-button.elm shows the following:

Could not find package elm-lang/core.

Maybe your elm-stuff/ directory has been corrupted? You can usually fix stuff
like this by deleting elm-stuff/ and rebuilding your project.

I tried deleting elm-stuff and running elm-reactor again with the same result.

[process-bot]

Thanks for the issue! Make sure it satisfies this checklist. My human colleagues will appreciate it!

Here is what to expect next, and if anyone wants to comment, keep these things in mind.

[sea-witch]

I just realized what it was. I was running an older version of Elm. After updating everything works fine.