When attempting to start the Veeam Backup Catalog service an error is generated in the Svc.VeeamCatalog.log file stating Attribute "LastSyncTimeUtc" was not found under the tree “”
This is caused when the unpacked_data.txt file is corrupted in some manner, either not presenting the proper information or being empty. The state of the file can be confirmed by going to the Veeam catalog location which by default is C:\VBRCatalog\Index\Machines\ (your path to the VBRCatalog folder may differ). Open the unpacked_data.txt file and confirm it looks like the below. The actual time synced will very.
# Unpacked guest index data of unregistered OIBs options
# Temporary unpacked guest index data
If your unpacked_data.txt does not look like the above rename the file to unpacked_data_old.txt, start the Veeam Catalog service and a new file will be created. This will allow the catalog service to start while keeping your Catalog information intact.