Canon EOS R Advanced User's Manual page 527

151: Transmission canceled
Automatic image transfer to the computer was somehow
z
interrupted.
To resume automatic image transfer, set the camera's power
g
switch to < 2 >, and then set it to < 1 >.
152: Card's write protect switch is set to lock
Is the card's write-protect switch set to the locked position?
z
Slide the card's write-protect switch to the writing position.
g
Responding to Error Messages
527