- check that you have a single folder open in VS code; this is different from a single-folder VS code workspace. First close all the currently open folders then open a single folder using the 'File > Open Folder' menu. The open folder should be the `beginner/apps` folder for the beginner workshop or the `advanced/firmware` folder for the advanced workshop.
- use the latest version of the Rust-Analyzer plugin. If you get a prompt to update the Rust-Analyzer extension when you start VS code accept it. You may also get a prompt about updating the Rust-Analayzer binary; accept that one too. The extension should restart automatically after the update. If it doesn't then close and re-open VS code.
- You may need to wait a little while Rust-Analyzer analyzes all the crates in the dependency graph. Then you may need to modify and save the currently open file to force Rust-Analyzer to analyze it.