PS4 does not start in safe mode even though update was made?

Strangely yesterday my PS4 switched to security mode and wanted me to install an update on it. Then I grabbed the next USB STICK and threw everything down and then put the file for the update on it.

I just played the update on the ps4. Then this started again and this picture came back

I repeated the whole thing the whole time, but still didn't work!

And before I completely flatten the PlayStation and lose all my data on it, I wanted to ask if there's a solution to get the ps4 running again on a different variant.
I really bought a lot and don't want to lose it all.

A friend of mine had you too, you can reset it completely but you have to download everything again. Ps: good luck

* download * or buy new?

because I'm already registered on the network, but I don't know whether all the content is stored there

All should be saved

For sure?