Plex does not install, HDD does not initiate, nothing works.. what is wrong?

I bought an EX4100 and wanted to install several 8TB discs.

Because I had to copy my data to a backup and back I made some tries before…
At first I put one in Slot1 - works.

I tried to install Plex -stuck at 0%, downloaded the bin and tried to install it manually - same, no progress at all.

Then I put another NEW WD Red 4TB in slot 4, just to try a bit. This HDD should not stay here…
So the WebIF only tells me “Festplatteninformationen
Das System ist ausgelastet. Bitte warten Sie, bis die System-LED blau leuchtet, bevor Sie ein weiteres Laufwerk installieren.” (sth. like: Information, the system is busy, please wait until installing other disks).
But nothing happens anymore, for hours!
So in this time, my second 8TB got ready, so I installed this - same here. The WebIf can only be used while blocking the layer with the website inspector by Firefox.
Restarts do not help either, nothing happens.
Via SSH i can not see a high system activity, it only idles… via smartmonctl, both disks are healthy.

So I thought… ok, no data, try a reset… via Webif…maybe you guess it? no progress, the dialogue starts and nothing happens.
Via SSH: factoryRestore.sh at the end it trys ti fetch some data from the Web, 403 code, reset and I can login with my old credentials - so not really a factory reset! And also no change at all…

So, lets try to format the volume…maybe you guess it this time?
Nothing, the WebIF is stuck at 0%… even after reboots.

So, whats wrong?!
I got the NAS “new” from the refurbished store and not used by another person.

And please dont say “use another browser”… same for chromium and opera on linux and android.

ok, complete 40s reset helped for the app problems…
and the disc problem could be solved by making a smart test run on another pc and after this plugging the drive to the ex4100…

but both does not sould like a good tested software/firmware…

Bogus conclusion, because just because YOU had issues does not mean the many others of us had even a small glitch. No problems here.

Glad you finally got it working, tho.