Hello,
there is a bug in the current version which causes that we offer defragmentation for some types of SSD driver, which is a complete nonsense and we apologize for that.
In the meantime, please do not use this feature in case you have an SSD drive and wait for the fixed version we are currently working on and shall be released later this week.
Thank you for the understanding and your patience.
Best regards,
Avast Cleanup team.