There is definitely a problem with the latest version, as I've tried downloading and installing it at least 3 times now and it always crashes right when I try to start up.
@Dave CCleaner I guarantee the majority of people that have posted about issues with your most recent update have already upgraded to BigSur 11.1.
This is a small snippet of the error report, which I hope provides enough details. Please fix the issue, we'd really appreciate it!
Process: CCleaner