Endless OS 4.0.2 was released on 15th December 2021 as an over-the-air upgrade only, to fix a major issue introduced in Endless OS 4.0.1 on 13th December 2021.
Computers with web safety enabled before upgrading to Endless OS 4.0.1 were no longer able to connect to the internet at all. This problem is resolved in this release.
If you are unable to go online after upgrading to Endless OS 4.0.1, open a Terminal window, type the following command, and press
pkexec eos-safe-defaults disable
Then restart your computer. If your problem is caused by this Web Safety bug, it should now be able to connect to the internet once again. Web Safety will be re-enabled when you update to Endless OS 4.0.2 or newer.
For full details on what's new in Endless OS 4, please see the release notes for Endless OS 4.0.0.