Backup cannot be created with the following errors in Plesk:
CONFIG_TEXT: [d6e19d1e-cdd6-111a-b6be-73445d704e47]: Unable to get attributes of the file C:\vhosts\example.com\logs\iis\W3SVC7\u_extend1.log: The process cannot access the file because it is being used by another process. The file will not be archived. [:94236416]
Cannot dump domain hosting content [The process cannot access the file 'C:\Program Files (x86)\Parallels\Plesk\PrivateTemp\tmp39325.tmp' because it is being used by another process.]
backup_logs_*.zip file only remains in backup's folder and cannot be automatically rotated later.
This issue has been considered as Plesk bug #PPPM-7412 and will be fixed in future product updates.
Exclude log files for a backup in Plesk > Backup manager > Schedule.