The error message is suggesting that Servosity was not able to read the index files on the local side. Please follow these steps below to force the backup to recreate the index files on the next backup job.
1) Make sure the backup-set is not running.
2) Delete the index files 'index.bdb' and 'r-index.bdb' from the Local Copy data. The index files can be found in the following directory of the Local Copy destination:
Local_Copy_Destination\Backup_server_name\account_name\files\backup_setID
Example location: F:\Servosity\backup1.servosity.com\Servosity_Backup\files\1318614174555
3) Perform the Local Copy backup afterward, the index files will be re-generated on-the-fly automatically.