@sanity/icons default export not found error after sanity init

This error is happening because you're accidentally running Sanity Studio v2 instead of v3. The warning about @sanity/icons default export and references to @sanity/base with the parts system (part:@sanity/base/sanity-root) are telltale signs of the older v2 architecture.

Here's what's likely happening: even though you ran sanity init, your project somehow got initialized with v2 dependencies instead of v3. This can happen if you have an older version of the Sanity CLI installed globally.

To fix this:

1. Update the Sanity CLI globally:

npm install -g @sanity/cli@latest

2. Delete your current project and create a fresh one:

# Remove the project directory
rm -rf your-project-folder

# Create a new project with the updated CLI
sanity init

3. Alternatively, if you want to keep the project, manually upgrade to v3:
   • Delete node_modules and package-lock.json (or yarn.lock)
   • Update your package.json to use Sanity Studio v3 dependencies (should be sanity@^3.x instead of @sanity/core and other v2 packages)
   • Run npm install again

How to verify you're on v3:

• Your package.json should have "sanity": "^3.x" as a dependency
• You should not see @sanity/base, @sanity/core, or @sanity/desk-tool in your dependencies (these are v2 packages)
• Your config file should be sanity.config.ts or sanity.config.js, not sanity.json

The issue you're seeing is that @sanity/icons removed its default export in newer versions, but v2's @sanity/ui still tries to import it the old way, causing this compatibility mismatch. Studio v3 uses the modern import structure and doesn't have this problem.

If you continue having issues after updating the CLI and reinitializing, check that you don't have any old Sanity packages cached or lingering in your global npm/yarn cache.