I am finding that RawTherapee is causing problems with my SD cards on iMac with OSX 10.12.3. Lexar Professional 633X SC1 (U3) 64 gig card formatted in Nikon D5300 camera. Shots taken in RAW and/or JPG. Files imported into Raw Therapee with no problem. Card properly demounted and removed from iMac and reinstalled in camera. Camera now says card is damaged and not useable. Put card back into iMac and format to FAT, then put into camera and reformatted there. Once done, no problems....until the next time I put card into iMac and import into Raw Therapee. I had this problem with older version of Raw Therapee and now with the newer, gtk3 version. This does not happen when I import into Adobe lightroom (which I am trying to get away from!) or iPhoto (Photo).