The NET::ERR_CERT_AUTHORITY_INVALID error is a common security warning that users may encounter in their web browsers when attempting to access certain websites. This error message indicates that the SSL/TLS certificate of the website has not been issued by a trusted certification authority (CA), thereby questioning the authenticity of the site and potentially compromising the security of the user's connection.

Causes of the Issue
Several reasons may lead to the NET::ERR_CERT_AUTHORITY_INVALID error, including:

• Certificate issued by an unknown or untrusted CA: Web browsers and operating systems maintain a list of trusted certification authorities, and if a website's certificate is not issued by one of them, the browser will display a warning.
• Self-signed certificate: Websites using self-signed certificates (created and signed by an entity that is not a trusted CA) also trigger this warning.
• Certificate chain issues: Sometimes, web servers improperly configure the certificate chain, causing the browser to be unable to verify the trustworthiness of the certificate.

Solutions for Website Administrators
Website administrators should ensure that their sites use certificates issued by trusted certification authorities. If this error occurs, the following steps should be taken:

• Certificate Verification: Verify that the certificate was correctly issued and is still valid.
• Chain Configuration: Check that all necessary certificate chains are correctly installed on the server to ensure the certificate chain is complete.
• Renewal or Replacement of Certificate: If the certificate is self-signed or issued by an untrusted CA, obtain a new certificate from a trusted certification authority.

Solutions for Users
Users encountering this error message should proceed with caution and consider the following steps:

• Verify the Website Address: Ensure that the website address is correctly entered and that you are on the expected webpage.
• Update the Browser: Check if you are using the latest version of your web browser, which includes an up-to-date list of trusted certification authorities.
• Contact the Website Administrator: If you believe the website should be trusted, inform the website administrator about the issue so they can address it.

The NET::ERR_CERT_AUTHORITY_INVALID error is an important warning that highlights potential security risks when establishing encrypted connections with a website. Both website administrators and users should approach resolving this issue with care to ensure the security and trustworthiness of internet communication.