Shooting touch football Friday night.
D700+80-200/2.0 with grip with AA's inserted for max frame rate. Kept flashing "Err" and only shot one frame at a time (despite set on continuous)
Turn off for a bit then on. sometimes shot a few fast frames. then back to "Err"

Wiped over lens contacts. no change.
Took grip off. No more "Err"

Today shooting indoor netball with grip - not a problem. No "Err"
Now I did use a freshly formatted card at netball, whereas at touch I had grabbed the camera in a hurry & used a card with plenty of images on the card already

Anyone been there, done that?
Is it as simple as using clean cards, or is that just a coincidence?