"specified cast is not valid" using "Only when mode is" for a Light Turn On Schedule

I’m using the Windows Phone SmartThings app to set the Light Turn On Schedule for a (CentraLite Switch). I’m trying to set the switch to turn on at sunset only when nobody is home. So, I select “Turn on using a schedule” and “Turn on at Sunset”. Then I expand “More options” and tap “Only when mode is” and I check the “Away” box. When I try to Save the update, I get this error: “specified cast is not valid” . I get the same error choosing other mode options.

I do not get the error when I eliminate the “Only when mode is” condition. What am I doing wrong and how can I fix this? Do I need to do something to configure/define Mode: Away?

thanks!