KVB is right, reset the camera. There is little a person can do if this happens. The usual stuff besides resetting is a know good battery (not an off brand) fully charged by a known good charger (not an off brand). A top quality full size SD card. And make sure there are no off brand accessories on the Rebel like a grip.
If all is not well after that, you might try formatting the SD on a Windows computer first.
EB
EOS 1D, EOS 1D MK IIn, EOS 1D MK III, EOS 1Ds MK III, EOS 1D MK IV and EOS 1DX and many lenses.
