Safari started some time ago to behave in an unpredictable way on my rMBP running the latest OS X version. It happens since OS X 10.11.2, if I remember correctly. What it does is this. After waking up the machine, it fails to open many web sites. Some of them work fine, others not at all. Of course I can check my internet connection using other computers and everything is OK. The solution is to quit and open Safari again. Then it behaves as it should. Not a really big problem, because it reopens and restores the previous session fast, but still ... This may be user-specific but I don't want to erase all history data. I don't care about cache but I would like to keep the links already visited. Safari had in the past a reset function which allowed the user to choose what to erase but this seems to be gone now. Anyone else with this problem and suggestions to solve it? Thanks!