Hi all - please use this topic to post feedback specific to 2021.06. Release-specific feedback is valuable to us, and consolidating it in a single topic is extremely helpful. Thanks in advance!
2021.06 Release Notes
This is not an admin issue. Most likely your Microsoft VC redist is corrupted by something else. Till you solve that you won't be able to install or run cbb.
Try reinstalling those from here. After successful install of the redist reboot and then retry the cbb install
https://aka.ms/vs/16/release/vc_redist.x64.exe
If you contact support they should be able to help you reinstall clean if your still have issues.