Avamar: Backup validation completes with exception with "ABV failed" error

Backup validation completes and reports a failure with the following error message:

avvcbimage Error <19702>: ABV failed

There are two potential root causes to this problem:

1. VMware Tools is either not installed on the VM, or it is not up to date.
2. A custom script used in the Validation Policy affects the validation workflow.
   
   To check if the script is failing, open the log from the Support Bundle and search for the following lines:

2022-06-29 08:02:21 avvcbimage Info <0000>: GetPropertyByMoref Succeeded
2022-06-29 08:02:21 avvcbimage Warning <16004>: Soap fault detected, Run Guest Script, Msg:'SOAP 1.1 fault: "":ServerFaultCode [no subcode] "A general system error occurred: vix error codes = (1, 0).
" Detail: <SystemErrorFault xmlns="urn:vim25" xsi:type="SystemError"><reason>vix error codes = (1, 0).
</reason></SystemErrorFault>
'
2022-06-29 08:02:21 avvcbimage Info <40729>: runGuestScript * status=0 pid=0'
2022-06-29 08:02:21 avvcbimage Error <19688>: runGuestScript failed

An example of a custom script:

echo "backup validation ran"
echo %date %time
exit /B 8008135

There are two solutions:

1. Install VMware Tools on the VM if not already installed. If VMware Tools is installed, update to the latest version.
2. Exclude the custom script from the Validation Policy.