Damaged unpacked_data.txt File Causes Veeam Guest Catalog Service to Not Start

The Veeam Guest Catalog Service fails to start and the Svc.VeeamCatalog.logDefault Location: C:\ProgramData\Veeam\Backup\ file contains an error similar to:

Attribute "LastSyncTimeUtc" was not found under the tree "".

or

Attribute "VmName" was not found under the tree "oib#". 

To resolve this issue:

1. Rename the unpacked_data.txt file to append .old after the file extension (unpacked_data.txt.old).
2. Start the Veeam Guest Catalog Service, and a new unpacked_data.txt file will be created.

The state of the file can be confirmed by going to the Veeam catalog location (default: C:\VBRCatalog\Index\Machines\).
Open the unpacked_data.txt file and confirm it looks like the below. The actual time synced will vary.

LastSyncTimeUtc=07/13/2020 16:13:05.054
####################################################
# Unpacked guest index data of unregistered OIBs options
KeepUnpackedInHours=48
####################################################
# Temporary unpacked guest index data