Are you tired of getting “Private key required to install a certificate‎‏‎‎‏‎” when trying to install a CA certificate under Android via the settings app? (It never works via the file browser directly. You have to go via, and I only paraphrase, as I only have GrapheneOS here, no LOS: Settings > something security > (more privacy and security?) > something login data/credentials/encryption > Install a certificate)

Just check

  • The certificate must be in PEM format. If it is in DER, you get the error above.
  • The file extension must be .crt or .cer. Not .pem. Otherwise you get a different error.