End users are getting certificate errors and are unable to connect to an application deployed...

Comprehensive and Detailed Explanation From Exact Extract:

When SSL/HTTPS inspection is enabled on a firewall, it intercepts and decrypts HTTPS traffic. This requires the firewall to present its own trusted certificate to the client device. If that certificate is expired, the client browser will display a certificate error and block access to the application. This is a common misconfiguration that breaks HTTPS communication.

Relevant Extract from CompTIA CloudNetX CNX-001 Study Guide — under “TLS/SSL Inspection and Certificate Management”:

“SSL inspection appliances must have valid certificates installed. Expired or untrusted certificates will result in browsers rejecting the HTTPS session and displaying errors to users.”

Other options:

A. Would prevent connection, but not result in certificate errors.

B. Blocked port 443 would prevent any connection, not cause cert errors.

C. Client-side certificates are not required unless mutual TLS is configured, which is not stated here.

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