Canon Lens Connection Error

[mclaughline]

I am a high school photo teacher.  We purchased a canon zoom lens EF 24-70 mm 1:4 L IS USM lens with a grant last year.  Unfortunately now we keep getting an error message saying there is a connection error with the lens.  I have tried cleaning the connection points but it still does not work.  Help?

[kvbarkley]

What camera?

Do other lenses work on the same camera?

How far back? If less than a year, it should still be under warranty, send it back.