The typings can only be a `.d.ts` file. Contact package author to fix it

[basarat]

Happens when using the latest compiler as a language service. Sample package : csx https://github.com/basarat/csx npm install csx.

I suspect that #4911 broke it ... it now looks at the csx.ts file and errors 🌹

[mhegazy]

yup. that would be a side effect of #4911. the fix would be to add the full extension in the typings field ("typings": "csx.d.ts").

We have got feedback about users wanting to include their .ts files and found the compiler changing its lookup rules to pick .d.ts files too restrictive.

We should remove the error though.