A few days ago my iMac froze up and crashed, I posted about it here. Since then it has happened again several times, and often webpages in Safari and Opera will crash as well. Has anyone else been having this problem, or is it just me? I updated to 10.11.5 not too long ago, and I also upgraded the RAM to faster 2133 MHz earlier this month. However, the crashing only started last Tuesday.