If your camera creates Raw images larger than the application can process, you will encounter random errors when calculating the profile and there will be no profile saved. The error may indicate an exposure problem, cropping error, or simply indicate some other random problem. The image size at which this problem will occur depends on several factors, including the memory available on the user system. You will typically see this problem with Raw images around 40 MB or larger. Until a permanent solution is available, the only current workaround is to shoot in a reduced sized Raw format.
The Canon 5Ds has three different RAW modes: S-RAW (small RAW), M-RAW (medium), and RAW (standard). The RAW (standard) file size is too large (~60 MB) but the S-RAW and M-RAW should work fine and the profile will be valid for all Raw formats.
The Nikon D800 and D810 have FX (full-frame) to DX (cropped-frame) mode. The Raw files are less than 20 MB in the DX mode but over 40 MB in FX mode so the user shoots the ColorChecker Passport target or 24-patch ColorChecker Classic target in DX mode and uses that to create the profile.
There may be other cameras that also have the options for reduced size Raw formats. Please check with your camera manufacturer. The ColorChecker Passport software development team is currently working on an update to address this large file issue. This update is due to be released early 2016.