Acrobat Reader DC stopped working

Hi, Acrobat Reader DC has stopped working at my computer (Macbook Air). What do I do? The program went down and after that I wasn't able to open any pdf-files. I don't get an error message, it just blinks as if it's about to open but then nothing happens. Have restarted the computer and reinstalled the program several times and updated to Mac OS Sierra, but nothing works.