CMS Strapi example - Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client

[msreekm]

Bug report

Describe the bug

CMS Strapi example - Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client on the server console and broken SSR for this page

To Reproduce

Steps to reproduce the behavior, please provide code snippets or a repository:

1. run cms-strapi-app example project ,

2. go to posts detail page (http://localhost:3001/posts/[slug])and do a full page refresh
3. check the server console for errors
4. Not sure if it is the side effect of this error- SSR of the posts page is also broken (if you do a full page refresh, it shows the loading state first and then post details) . I noticed this in other CMS examples too ,so this may be a different issue.

Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client at ServerResponse.setHeader (_http_outgoing.js:526:11) at DevServer.sendHTML (/Users/sreekumarmenon/projects/cms/cms-strapi-app/node_modules/next/dist/server/next-dev-server.js:23:5) at DevServer.render (/Users/sreekumarmenon/projects/cms/cms-strapi-app/node_modules/next/dist/next-server/server/next-server.js:49:37) at runMicrotasks (<anonymous>) at processTicksAndRejections (internal/process/task_queues.js:97:5) at async Object.fn (/Users/sreekumarmenon/projects/cms/cms-strapi-app/node_modules/next/dist/next-server/server/next-server.js:35:852) at async Router.execute (/Users/sreekumarmenon/projects/cms/cms-strapi-app/node_modules/next/dist/next-server/server/router.js:28:28) at async DevServer.run (/Users/sreekumarmenon/projects/cms/cms-strapi-app/node_modules/next/dist/next-server/server/next-server.js:44:494) at async DevServer.handleRequest (/Users/sreekumarmenon/projects/cms/cms-strapi-app/node_modules/next/dist/next-server/server/next-server.js:13:133) { code: 'ERR_HTTP_HEADERS_SENT' }

Expected behavior

No Error and Posts detail page is server rendered.

System information

• OS: macOS
• Browser (if applies) All
• Version of Next.js: latest
• Version of Node.js: 12.16.1

[timneutkens]

Try upgrading to next@canary

[SalahAdDin]

@timneutkens After doing this i don't get that error, yes, but i still don't get any result.

[msreekm]

@timneutkens thanks , http header error is fixed with v9.4.5-canary.23 , SSR is still broken (styling) ,it could be unrelated to the http header error, since it is happening for all CMS examples