KB1857: Unable to allocate processing resources
https://www.veeam.com/kb185713.02.2014 · See Enabling Parallel Processing. Remember to not under-allocate your Veeam Backup server, especially if it is your backup proxy. If the configuration database is installed on a local SQL instance (the default installation), then SQL Express should be allocated 1 CPU core and 1-1.5 GB RAM when planning your resource usage.