Mac - PostgreSQL problems

Hello,
I am having an error message. See attachements.
I did not do anything strange, except rebooting my laptop.
What the hell is this problem and how can it be solved?
I am not going to delete everything just to loose my database.
I reinstalled postgress 9.6 via the site you provided but it does not solve anything at all. I rebooted like 10 times, no succes.
I have the feeling postgress is not started and I also don't know how to start it on my mac.
Thanks for helping.
I am having an error message. See attachements.
I did not do anything strange, except rebooting my laptop.
What the hell is this problem and how can it be solved?
I am not going to delete everything just to loose my database.
I reinstalled postgress 9.6 via the site you provided but it does not solve anything at all. I rebooted like 10 times, no succes.
I have the feeling postgress is not started and I also don't know how to start it on my mac.
Thanks for helping.