show an error beside the image name in the registration view and adaption of the itk error massage:

e.g: "<imagename> could not be processed. No 2D images. <showImageDimensions> <pixeltype> <...>"

instead of

"itk::ERROR: Image(0x7f80d7161d40): A spacing of 0 is not allowed: Spacing is [0, 0]"

To reproduce load an 2D DWI image and try to start the registration. Please ask for image data.