Mount usb disk with `disk & devices` not working on fresh install

I have installed NixOS with Plasma and added the usbutils, udiskie and udisks and

services.devmon.enable = true;
services.gvfs.enable = true;
services.udisks2.enable = true;

When I plug in an usb disk, the disk & devices pops up but I cannot properly mount the disk. The error is

could not enter folder /run/...

I can mount the partition on the usb drive with sudo mount /dev/sdc1 /mnt1 and read or write there.
which piece is missing to make the Plasma tool work?