Big Sur needs an internet connection to install - but I am connected

Tips for upgrading to Big Sur and Especially the Empty Space Requirements of 36 GB of Empty Space but suggest 50 GB

Are there any AntiVirus, Disk Cleaner, Optimizers, Un-installers, etc installed which should be removed as per Developers Instructions. They are useless, unneeded, cause havoc and interfere with the normal operation of the OS and may even Corrupt the OS requiring a Reinstallation. 

Hi, I had the same problem. MacBookPro, 2019, Catalina to Big Sur. The remark about anti virus made me try this which worked for me. I opened Norton Security, opened the « Advanced » settings and disabled in the Firewall option the bottom « Connection Blocking » (so it becomes grey instead of green). This will give a warning message by the Norton software « At Risk : Your Mac is at risk while warning the Internet » but don’t click on « Fix it ». When I continued the installing, I didn’t encountered any problem anymore. Once finished the installation I put the « Connection Blocking » back to green. I hope this helps.

Are there any AntiVirus, Disk Cleaner, Optimizers, Un-installers, etc installed which should be removed as per Developers Instructions. They are useless, unneeded, cause havoc and interfere with the normal operation of the OS and may even Corrupt the OS requiring a Reinstallation. The Built-in Security of Big Sur is all that is required.

There are no known Viruses in the wild that self replicate and affect macOS. There are Malware and Adware that does affect macOS and are often times downloaded as part of an Application from Third Party UnTrusted Site and get installed along with the Application.

And Norton software is notorious, on this ASC Forums , to one of the Worst for messing up the perfecting running macOS.

The Caution against running any AV Software has been offered.

How do you expect a response when you have given us no information to evaluate? What does "trying for months" mean? What happens? What messages does you receive? Also, it is important for you to state the year and model of your Mac to ensure that it is compatible with Big Sur. Please help us to help you.