07-26-2018 10:48 AM - edited 07-26-2018 01:21 PM
I can confirm the bug is still present in DPP 4.8.20 :-(
Is the firmware of your G15 up to date? And if so, does the problem still occur with pictures that were shot with the latest firmware in place?
There would seem to be two possibilities. Either a bug in DPP 4 is causing some G15 RAW files not to be handled correctly, or the G15 sometimes produces a subtly corrupted RAW file that confuses DPP 4. If the latter, it's conceivable that an intervening firmware update has fixed the problem (possibly accidentally), which could account for Canon's seeming inability to find what should be a fairly conspicuous bug. (That's assuming, of course, that they've spent some time looking for it, and I guess we have to give them the benefit of the doubt.)