I really tried to figure out what could be the problem here, but i give up. Maybe somebody can help me!
After a fresh install of Proxmox 5.4, i try an "apt-get update" and instand i got an runtime-error:
Linux bks003 4.15.18-12-pve #1 SMP PVE 4.15.18-35
the /etc/apt/source.list (i tried...