I have been getting annoyed with having to receive a 1 time security code by email and enter it on the startup menu. So....I decided to finally sign up for the security code. I have been following the directions and attempting this. I have doing this for literally over an hour to no avail. This is sickening. I signed in to my account. Downloaded the mobile app from Google play store. Selected the "Get mobile security" option when prompted on their website. It gave me a serial number and automatically entered it on the line for the serial number in the signup box. I entered that serial number in the mobile app as directed. Triple checked before I selected "ok" in the mobile app. Mobile app is generating security key with a timer to enter it in website. I enter the security key in the signup website before timer even comes close to expiring. I constantly get an "ERROR: CAN'T LOCATE SERIAL NUMBER" What the F%$CK is going on? Solved: I had to go to settings on the mobile app and choose "Sync now". After the sync it worked.