Canon EOS REBEL T7i Instruction Manual page 440

Troubleshooting Guide
Shooting-Related Problems
The lens cannot be attached.
The camera cannot be used with EF-M lenses (p.49).
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The viewfinder is dark.
Install a recharged battery in the camera (p.36).
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No images can be shot or recorded.
Make sure the card is properly inserted (p.39).
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Slide the card's write-protect switch to the Write/Erase setting (p.39).
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If the card is full, replace the card or delete unnecessary images to
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make space (p.39, 363).
If you try to focus in the One-Shot AF mode and the focus indicator
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<o> in the viewfinder blinks, a picture cannot be taken. Press the
shutter button halfway again to refocus automatically, or focus
manually (p.52, 140).
The card cannot be used.
If a card error message is displayed, see page 39 or 453.
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An error message is displayed when
the card is inserted in another camera.
SDXC cards are formatted in exFAT. This means that if you format a

card with this camera and then insert it into another camera, an error
may be displayed and it may not be possible to use the card.
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