How do you resolve a 'No internet connection found' and 'General connection failure' error?

Lumion 2023 and Lumion 2024:

Earlier versions:

1. Here's how:

1.1: If your PC can access the internet, please follow these instructions:

• Knowledge Base: How do you resolve anti-virus and firewall problems?

1.2: If your PC can't access the internet, please follow these instructions:

• Knowledge Base: Can you use Lumion without an internet connection?