Issues you may run into

Hard to explain “Foregin key constraints failed” errors

This might be a caching issue. Did you do a pnpm reset when the dev server was running? Try quitting the dev server, running pnpm --filter core clear-cache and then restarting the dev server.

This should be a dev only error, although it might also appear when build previews are deployed (as pnpm reset is currently (March 25, 2025) run during the build).

Typescript dev server keeps crashing

This might be due to extremely large types, but it’s likely due to a bug in another VS Code extension or a bug in a Typescript extension.

next typescript plugin

Most often, this is due to the next typescript plugin. Sadly, next does not want to disable auto adding this plugin to core/tsconfig.json, see https://github.com/vercel/next.js/discussions/39942 .

So either, we patch next to not do this, which can accomplished by doing something like this

 
      if (suggestedActions.length < 1 && requiredActions.length < 1) {
          return;
      }
-     await _fs.promises.writeFile(tsConfigPath, _commentjson.stringify(userTsConfig, null, 2) + _os.default.EOL);
+    // await _fs.promises.writeFile(tsConfigPath, _commentjson.stringify(userTsConfig, null, 2) + _os.default.EOL);
      _log.info('');
      if (isFirstTimeSetup) {
          _log.info(`We detected TypeScript in your project and created a ${(0, _picocolors.cyan)('tsconfig.json')} file for you.`);

You might also need to do the same in node_modules/.pnpm/next@.../node_modules/next/dist/esm/lib/typescript/writeConfigurationDefaults.js (the ESM version).

Another solution is to use the VS Code version of Typescript rather than the workspace version. Do CMD + SHIFT + P and then > Typescript: Select TypeScript version and then select Use VS Code Version. Make sure they are both using the same version.

Rogue VS Code extensions

Some common VS Code extensions can also cause issues.

Ones I’ve observed to cause issues are:

• Astro plugin
• better-ts-errors

dispatcher.getOwner is not a function

If you see something like

TypeError: dispatcher.getOwner is not a function
    at getOwner (/node_modules/.pnpm/react@19.1.1/node_modules/react/cjs/react.development.js:162:54)
    at process.env.NODE_ENV.exports.createElement (/node_modules/.pnpm/react@19.1.1/node_modules/react/cjs/react.development.js:1031:9)
    at Tester

this likely means that React is trying to render a component with no NODE_ENV set. This has been observed to happen when running the site-builder with pnpm start with no NODE_ENV set, eg when running pnpm start.