The error given is
Attempted to load trait "ExclusionFilter" from namespace "Akeeba\Component\AkeebaBackup\Administrator\Model\Mixin".
Did you forget a "use" statement for another namespace?
However, the manual back up is working.
Don't know where is the log file to attach it.
EXTREMELY IMPORTANT: Please attach a ZIP file containing your Akeeba Backup log file in order for us to help you with any backup or restoration issue. If the file is over 10MiB, please upload it on your server and post a link to it.