Hi, I wasn't able to find any answers in oder threads, so here is the situation. I updated my Macbook Pro 17 inch (2010, I know its old) to 10.11.5 from 10.11.3 and it worked fine for 2 days, no problems at all and I could work perfectly on it like I always used to. Then suddenly, after each click on a file or button the beachball appears. For example it takes 10 seconds or longer to open up a folder. To playback a music file the same, and it can't playback without interruption, including beachball. If I try to change the volume also the same, the beachball appears and after a while I can change the volume button. One remarkable thing is, that after a restart, sometimes I can use the computer without any problems for about 20 seconds or so. Then it starts behaving as mentioned before. I have a 500GB HDD in there btw. Any hints would be very appreciated, thank you!