Hi Kilonga,
I am not with Laminar Research; just a flight simmer.
Have you disabled your anti-virus software? Do you have administrator rights? Are you running a Mac system or a windows based system? Are you running a Steam version or a genuine Laminar Research version of X=Plane? As you have indicated you are trying to download scenery I presume you are using the digital "download" version.
Does your machine meet the system requirements which can be found here at https://www.x-plane.com/kb/x-plane-11-system-requirements/
Finally, attach your log.txt file so that others can have a look for a possible reason for the cause of your dilemma. The log.txt file is generated immediately after you shut down or your system crashes.
Glenn