I'm the one who asked the question. I solved it myself: create a new user account and it never happend again in it!!
I remember running `rm -rf ~` in my terminal (mistakenly). That might have broken something important. Why don't you try it out @simenleknes!
As you asked my hardware, I copied info from `About This Mac`:
* MacBook Pro (Retina, 15-inch, Mid 2015)
* Processer: 2.5 GHz Quad-Core Intel Core i7
* Memory: 16 GB 1600 MHz DDR3
* Startup Disk: Macintosh HD
* Graphics: AMD Radeon R9 M370X 2 GB
Intel Iris Pro 1536 MB