Unresolved reference for all dependencies

I have a problem with the VSCode editor underlining all names from external dependencies in red, and not being able to give me any suggestions. My guess is that it is the language server that does not find the dependencies. (I have had problems with this before, but I have been able to resolve it.)

- The error message is "kotlin(UNRESOLVED_REFERENCE)".
- I don't have problems with the stand library, nor with names in the current project. It is only external dependencies.
- It is a gradle project. The build.gradle file is [here](http://magnusgunnarsson.se/build.gradle).
- I have the same problem in my other kotlin projects. A java project I have does not have this problem.

The output from the language server can be found [here](http://magnusgunnarsson.se/output.txt).

How do I debug this? How does the plugin/language server find dependencies? Is there a way to check which external libraries the language server has found? I'm using VSCode 1.81.1 on macos Ventura 13.5 with the Kotlin plugin (fwcd). I have kotlin 1.9.0 and JRE 20.

Start by reviewing the linked build.gradle and output.txt, then inspect how the Kotlin language server discovers dependencies for a Gradle project. Reproduce the issue with the reported Kotlin, JRE, VSCode, and macOS versions. Done means external dependency names no longer produce kotlin(UNRESOLVED_REFERENCE) and suggestions are available.

Written by the indexing model from the issue text.