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I just bought a new SSD; installed High Sierra on it using my Mac Mini; then put it inside my 2010 MBP as the main drive. On the Mac Mini it worked fine as the main drive. In the MBP, Console is telling me tons of processes keep crashing; I can’t open several apps (eg Safari & Calendar); and reportCrash is eating up my CPU & RAM. Why is this happening, and how do I resolve it??

A couple of things could be giving you issues. Your machines BUS is SATA II 3.0 GHz. Most of the new SSD drives are SATA III 6 GH. So make sure your drive is backward compatible. Next change your hard drive I/R cable to the heavier duty 2012 model. UPDATE Here’s the cable to use: MacBook Pro 13" Unibody (Mid 2012) Hard Drive Cable Here’s how to install it: MacBook Pro 13" Unibody Mid 2012 Hard Drive Cable Replacement Sometimes you can only put in one of the retainer screws and sometimes you have to modify the retaining bracket. Here’s how to mount it so it will not get damaged again

Note the tape on the bottom of the case and the 3M extreme mounting ting tape on either side of the cable to prevent the bottom case comping into contact with the cable. Your information on all SSD drives being backward compatible is very incorrect. Please tell us what drive you are trying to use.