If this is only happening on this process then remove the reminders that have this issue, save the process and re-add them back in. It's possible that the old reminder had a value of false on the Is Active field. The other option is to update the reminder window to set this field to ReadWrite instead of readonly and then go into the process and set them all to Active = True by checking this box.
Craig Middelstadt
Senior ITSM Consultant
Mobile: (801) 300-3412
cmiddelstadt@ncsi.us