Splunk Universal Forwarder upgrade to 9.1.3 is failing with Copy Error "Setup can not copy the file SplunkMonitor NoHandleDrv.sys". Attached the error message
There is a known issue where version 9.1.3 is unable to be installed or upgraded to: https://docs.splunk.com/Documentation/Forwarder/9.1.3/Forwarder/KnownIssues
Could you try the suggested workaround:
Install UF while passing the following feature flag:
msiexec.exe /i $SPLUNK_MSI_PACKAGE USE_LOCAL_SYSTEM=1