Lense error, restart your camera

If i told you to smack it around a bit would ytou believe me?

But that is the fix Canon use to get rid of these errors 98% of the time.
Charge or change the battery, insert it tuen camer on when it goes off smack it hard into your palm a few times and turn it back on.
Just incase there is some dirt/dust stopping the lens from extending blow a can of compressed air around it and give it another few slaps . Sometimes after about 20-30 ngoes of this the camera will jump back into service Believe me it does work nearly all the time Canon charged me $90 to do this trick

Lens errors are fairly common. Usually it's sand or grit interfering with the lens extension mechanism. Or the camera's been dropped with the lens extended. Or the camera has been powered on, but the lens had been blocked preventing its extension. Or the battery ran down with the lens extended ...

Here are some things that you can do to try to correct it. They only seem to work for less than 50% of the lens errors, but if the camera is out of warranty, they're worth a try.