I have been haveing an issue with my 85 1.8 on my 6D. Every once in a while I get the error 01. Only this lense on this body. At first I thought it was the lense, cleaned contacts etc. Still happens. I am using a vello grip but because it doesnt happen on my other lenses I suspected the lense. It got bad today, happening about 40 percent of the shots. I removed the grip and errors have been gone.
Anyone else had this problem?
Guess I will be splurging for the canon grip 

