The problem

While setting up my new personal laptop with Fedora 40 I noticed that the Postman’s flatpak version refused to start after I logged in, after running it from the command line with flatpak run com.getpostman.Postman I noticed the following error:

Main~handleUncaughtError - Uncaught errors [Error: ENOENT: no such file or directory, open '/home/user/.var/app/com.getpostman.Postman/config/Postman/proxy/postman-proxy-ca.crt'] {
  errno: -2,
  code: 'ENOENT',
  syscall: 'open',
  path: '/home/user/.var/app/com.getpostman.Postman/config/Postman/proxy/postman-proxy-ca.crt'
}

The fix

After searching through the comments on Gnome Software I found a comment from Alexandre DeBusschere that solved the issue:

• Go to ~/.var/app/com.getpostman.Postman/config/Postman/proxy

• Run the following command to generate a valid certificate:

  openssl req -subj '/C=US/CN=Postman Proxy' -new -newkey rsa:2048 -sha256 -days 365 -nodes -x509 -keyout postman-proxy-ca.key -out postman-proxy-ca.crt

The application should work just fine now!