Hi guys, after a lack of answers in the High Sierra forum, I thought I’d ask here I have a flashed 4,1 with a 3.46GHz 6-core cpu, flashed 7950 and a Samsung ssd mounted on a sonnet tempo carrier. Up to now, it’s been awesome but now I have an issue which I can’t fix and is bad en Ugh that m looking at getting an iMac! Essentially, in the photos app, most images display as red boxes. Sometimes only as thumbnails and sometimes as thumbnail and image. If I take a photo and add it to photos, it’s ok until I open it and zoom in. At which point it goes red and stays that way. The extra irritating thing is that this propagates to my iCloud images and destroys all the thumbnails and has also wrecked a few master images too! The library seems to mostly download onto my old laptop without problems and I have backups of course but this makes my Mac Pro useless as photography is kinda its main use........... I’ve tried reinstalling from the combo updater. I’ve tried a different drive mounted the conventional way. I’ve tried a complete fresh install on a fresh drive. I’ve tried the old gtx 120 (and that seems to make white rectangles instead of red) and I’ve tried a different screen. I’m out of ideas. I can only assume that the rest of you with similar upgraded cMPs done have this issue. So what could it be? RAM? CPU? I’m already on my second power supply. I also checked and it’s the same with all other accounts on the machine. Save me before I buy an emergency iMac (which will mean no modular Mac Pro or 2018 iMac or whatever as whatever I buy will have to last a good few years). I can’t afford or justify the iMac pro.