[2020] Luckily, I received access within the first 30 minutes of streams today. However, I'm running into this error repeatedly despite loads of troubleshooting. Looking for any help to resolve the issue before the beta launches! Thank you in advance!

I believe it is related to the virtual machine. I believe Riot's anticheat has virtual machine detection and doesn't allow them.

The anticheat is installed as part of the installation process.

There was a League of Legends forum post about anticheat and virtual machines which provided some context as to why virtual machines were not supported but the League forums are gone now :(.