When there is any problem with WiFi such hardware failure or software crash which results in disappearing of the WiFi signal the letter "s" in the Roqos logo of your Roqos Core RC10 and RC20 starts blinking slowly.
To fix this issue, you can simple power cycle the unit. If it continues please contact Roqos Customer Support at support.roqos.com or send email to support@roqos.com.