iOS 11 introduces a new default “High Efficiency” Camera Capture format for both images and video content.
High Efficiency Image File Format (HEIF) with the .HEIC extension is now the default for all iOS 11 camera image content
High Efficiency Video Coding (HEVC) is now the default for all iOS 11 camera video content
HEIF and HEVC formats are currently not supported by the My Cloud Client apps at this time.
However, you can set iOS 11 cameras to the “Most Compatible” Camera Capture format when auto backup and thumbnail preview is required on a My Cloud. The “Most Compatible” Camera Capture format option uses .JPEG and H246 .MOV formats.
Tap Settings>>Tap Camera>>Tap Format>>Tap Most Compatible