Hi,
we are sorry that you have such issues with Cleanup. In order to be able to analyze the problem and fix it we would need the log files from you computer.
They are located here: c:\ProgramData\AVAST Software\Tuneup\log. Please copy all files from the folder, pack them and upload them somewhere or you can use our public FTP server ftp.avast.com/ftp/incoming/ and log in as anonymous user.
Thanks!