Windows FLR fails with "Failed to create or open file [C:\Windows\system32\config\systemprofile\"

When attempting to perform a Guest OS File Level Restore from a Windows Filesystem the mount Backup Browser displays the error:

The system cannot find the path specified.
Failed to create or open file [C:\Windows\system32\config\systemprofile\...\veeamflr-.flat].
Agent failed to process method {Mount.GenericMount}.

On the machine where the Veeam Backup & Replication Console was launched and the Mount Server assigned to the Repository where the backup files are stored, ensure that the following regitrisy values exist.

Key Location: HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment 
Value Name: TMP
Value Type: Expandable String Value
Value Data: %SystemRoot%\TEMP

Key Location: HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment 
Value Name: TEMP
Value Type: Expandable String Value 
Value Data: %SystemRoot%\TEMP

Reboot after creating.

PowerShell cmdlet to create registry values:
^{Note: These powershell cmdlets do not check if the registry values exist or are set to a different value.}