When I'm going to deploy my react project even with this error "findDOMNode is deprecated in StrictMode." will it fail during deployment? This error was due to Material-UI's persistent drawer, dialog, and muidatatable.
No. It's a harmless error because Material-UI uses a deprecated method somewhere that triggers in StrictMode. You won't see that error in production since StrictMode is only available in development. It's been going for a while and they plan to fix it in version 5, so just wait. See this issue here.