Hi Carolyn,
The reason you cannot uninstall Adaptable is because you are using it as your main theme.
You need to use the Theme Selector to choose the Clean theme. Once you have set Clean as your default theme, then you will be able to Uninstall the Adaptable theme.
Please be aware that uninstalling will wipe out all the settings like colours & images that have been selected / uploaded via this theme, also block regions and page layouts if different than the normal Moodle layouts.
If you get stuck please let me know.
Thanks
Mary
