slider revolution update says package not available
When attempting to update Slider Revolution via the BeTheme "Install Plugins" page, I click on "Update" (6.5.19 to 6.6.7), the page displays:
Updating Plugin: Slider Revolution
Update package not available.
Can someone provide some insights as to what the issue might be, or where more specific troubleshooting information can be found?
Many thanks in advance.