Canon EOS Rebel T3 18-55mm IS II Kit Instruction Manual page 30

Installing and Removing the Battery and Card
When the access lamp is lit or blinking, it indicates that images are
being written to or read by the card, being erased, or data is being
transferred. When the access lamp is lit or blinking, do not open the
card/battery compartment cover and never do any of the following.
Otherwise, the image data may be destroyed or the card or camera
may be damaged.
• Removing the card.
• Removing the battery.
• Shaking or banging the camera around.
If the card already contains recorded images, the image number might
not start from 0001 (p.158).
Do not touch the card's contacts with your fingers or metal objects.
If a card-related error message is displayed on the LCD monitor, remove
and reinsert the card. If the error persists, use a different card. If you can
transfer all the images on the card to a computer, transfer all the images
and then format the card with the camera (p.44). The card may then
return to normal.
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