Error installing Open Plex



I'm trying to install Open Plex on my Mac Mini 4.1 with MacOS High Sierra.
I downloaded the three scripts and then ran the installer that became available. Two buttons - ´Install´and ´Exit´ for Open Plex became available. I pressed the obvious install - and waited. It says to be patient on the installer window and also in the install guide.
I waited for about 24hrs. No further dialog box became available.

Does anyone have any pointers or help?