Why isn't Tasker activating Profile? I have created a profile with Tasker to accomplish a simple function, activate WiFi every 10 minutes and if the phone connects to a network leave WiFi on, otherwise turn it off and scan again in 10 minutes. This is my setup:

 
Profile Big / Task Big

WiFi Scan profile never activates (it doesn't get green and the Tasker notification says "no Active Profile"). When I activate Tasker it turns off my WiFi but never turns it on again. It is very strange; is it a Tasker bug? I am running Android 4.1.2 on a Galaxy S2.
While trying to explain where to find that "4th tab", I just see where your problem is:

You use the %WIFI variable to check for a) On/Off and b) the connection mode. Either it is On/Off, or it holds connection info. The first is %WIFI, the other %WIFII:


  WiFi Info
  %WIFII
  When connected to an Access Point (AP), shows human-readable data about the AP. When not connected, show details of the most recent Wifi scan results for nearby APs.
  
  WiFi Status (dynamic)
  %WIFI
  Whether WiFi is on or off. Note: if WiFi is enabling or disabled, in fact anything but enabled, it's classed as off. 


Source: Tasker UserGuide



Now back to the original explanation about that "4th tab":

You see some tabs in both pictures. In the first, "Profiles" is selected, in the second "Tasks". In both pictures you see another tab "Scenes". Right to that is one more, "Variables":



But regardless of that: For debugging, you can always to add another item to your task, "Notify", and have it either popup the %WIFI (or whatever variables) content or add it to your notification bar. This is good for debugging.